### Godot version

4.0.dev Beta 14

### System information

Windows 10 and Linux (Pop!_OS 22.04)

### Issue description

When opening a UTF-8 text file with an emoji or other unicode character, the line will not show up and the editor starts producing a number of errors in output. Here is the output:

--- GDScript language server started ---
  U_ILLEGAL_ARGUMENT_ERROR
  modules/text_server_adv/text_server_adv.cpp:4389 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:3837 - Condition "!sd" is true. Returning: TextServer::ORIENTATION_HORIZONTAL
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:3837 - Condition "!sd" is true. Returning: TextServer::ORIENTATION_HORIZONTAL
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:3837 - Condition "!sd" is true. Returning: TextServer::ORIENTATION_HORIZONTAL
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5829 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  U_ILLEGAL_ARGUMENT_ERROR
  modules/text_server_adv/text_server_adv.cpp:4389 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:3837 - Condition "!sd" is true. Returning: TextServer::ORIENTATION_HORIZONTAL
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:3837 - Condition "!sd" is true. Returning: TextServer::ORIENTATION_HORIZONTAL
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5730 - Condition "!sd" is true. Returning: nullptr
  modules/text_server_adv/text_server_adv.cpp:5741 - Condition "!sd" is true. Returning: 0
  modules/text_server_adv/text_server_adv.cpp:5818 - Condition "!sd" is true. Returning: 0.0
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5770 - Condition "!sd" is true. Returning: Vector2i()
  modules/text_server_adv/text_server_adv.cpp:5803 - Condition "!sd" is true. Returning: Size2()

### Steps to reproduce

Add a text file and paste in an emoji into the text resource file then open it in the editor.

### Minimal reproduction project

[FileIOGuide.zip](https://github.com/godotengine/godot/files/10477742/FileIOGuide.zip)

int64_t limit = p_pos;
	if (p_sd->text.length() != p_sd->utf16.length()) {
		const UChar *data = p_sd->utf16.get_data();
		for (int i = 0; i < p_pos; i++) {
			if (U16_IS_LEAD(data[i])) {
				limit--;
			}
		}
	}
	return limit;
}
int64_t TextServerAdvanced::_convert_pos_inv(const ShapedTextDataAdvanced *p_sd, int64_t p_pos) const {
	int64_t limit = p_pos;
	if (p_sd->text.length() != p_sd->utf16.length()) {
		for (int i = 0; i < p_pos; i++) {
			if (p_sd->text[i] > 0xffff) {
				limit++;
			}
		}
	}
	return limit;
}
void TextServerAdvanced::invalidate(TextServerAdvanced::ShapedTextDataAdvanced *p_shaped, bool p_text) {