### Godot version

4.2.dev 80de898d721f952dac0b102d48bb73d6b02ee1e8

### System information

OpenXR

### Issue description

The Godot 3 OpenXR plugin supported obtaining boundary/guardian information in order to obtain play space logic. While we do have a function in the `XRInterface` in Godot 4 that is supposed to retrieve this information (`get_play_area`) it is not implemented on the Godot 4 `OpenXRInterface`.

This logic needs to be ported.

### Steps to reproduce

Call `get_play_area`, be amazed by it not returning data :P

### Minimal reproduction project

Any XR project.
if (!is_interaction_profile_supported(p_ip_path)) {
		return false;
	}
	const OpenXRInteractionProfileMetadata::IOPath *io_path = OpenXRInteractionProfileMetadata::get_singleton()->get_io_path(p_ip_path, p_io_path);
	
	ERR_FAIL_NULL_V_MSG(io_path, false, "OpenXR: Unsupported io path " + String(p_ip_path) + String(p_io_path));
	if (io_path->openxr_extension_name == "") {
		
		return true;
	}
	if (!is_extension_enabled(io_path->openxr_extension_name)) {
		
		print_verbose("OpenXR: IO path " + String(p_ip_path) + String(p_io_path) + " requires extension " + io_path->openxr_extension_name);
		return false;
	}
	return true;
}
void OpenXRAPI::copy_string_to_char_buffer(const String p_string, char *p_buffer, int p_buffer_len) {
	CharString char_string = p_string.utf8();
	int len = char_string.length();
	if (len < p_buffer_len - 1) {
		
		memcpy(p_buffer, char_string.get_data(), len);
		p_buffer[len] = '\0';
	} else {
		memcpy(p_buffer, char_string.get_data(), p_buffer_len - 1);
		p_buffer[p_buffer_len - 1] = '\0';
	}
}
bool OpenXRAPI::create_instance() {