### Godot version

4.x

### System information

Windows 10

### Issue description

The `Search Result` panel is not correctly updated when changing the theme.

https://user-images.githubusercontent.com/66004280/208964493-d0423b78-3418-44c9-95ed-822fd34c4720.mp4



### Steps to reproduce

1. Search something
2. Change the theme

### Minimal reproduction project

--
_search_text_line_edit->set_h_size_flags(Control::SIZE_EXPAND_FILL);
	_search_text_line_edit->connect("text_changed", callable_mp(this, &FindInFilesDialog::_on_search_text_modified));
	_search_text_line_edit->connect("text_submitted", callable_mp(this, &FindInFilesDialog::_on_search_text_submitted));
	gc->add_child(_search_text_line_edit);
	_replace_label = memnew(Label);
	_replace_label->set_text(TTR("Replace:"));
	_replace_label->hide();
	gc->add_child(_replace_label);
	_replace_text_line_edit = memnew(LineEdit);
	_replace_text_line_edit->set_h_size_flags(Control::SIZE_EXPAND_FILL);
	_replace_text_line_edit->connect("text_submitted", callable_mp(this, &FindInFilesDialog::_on_replace_text_submitted));
	_replace_text_line_edit->hide();
	gc->add_child(_replace_text_line_edit);
	gc->add_child(memnew(Control)); 
	{
		HBoxContainer *hbc = memnew(HBoxContainer);
		_whole_words_checkbox = memnew(CheckBox);
		_whole_words_checkbox->set_text(TTR("Whole Words"));
		hbc->add_child(_whole_words_checkbox);
		_match_case_checkbox = memnew(CheckBox);
		_match_case_checkbox->set_text(TTR("Match Case"));
		hbc->add_child(_match_case_checkbox);
		gc->add_child(hbc);
	}
	Label *folder_label = memnew(Label);
	folder_label->set_text(TTR("Folder:"));
	gc->add_child(folder_label);
	{
		HBoxContainer *hbc = memnew(HBoxContainer);
		Label *prefix_label = memnew(Label);