### Godot version

v4.0.beta.custom_build [13f0158]

### System information

Windows 10

### Issue description

When doing operations (`begin_complex_operation` and `end_complex_operation`) with multiple selections in TextEdit, some of these selections don't revert upon undo. This behavior is affects some of script editor's operations, like duplicate selection and delete lines.

### Steps to reproduce

Open script editor, make multiple selections. Keep in mind what you have selected. Do duplicate selection (ctrl+shift+D). Undo (ctrl+Z). Compare the result to what you remember.

### Minimal reproduction project

N/A
Vector<int> caret_edit_order = get_caret_index_edit_order();
	for (int i = 0; i < caret_edit_order.size() - 1; i++) {
		int first_caret = caret_edit_order[i];
		int second_caret = caret_edit_order[i + 1];
		
		if (has_selection(first_caret) && has_selection(second_caret)) {
			bool should_merge = false;
			if (get_selection_from_line(first_caret) >= get_selection_from_line(second_caret) && get_selection_from_line(first_caret) <= get_selection_to_line(second_caret) && (get_selection_from_line(first_caret) > get_selection_from_line(second_caret) || get_selection_from_column(first_caret) >= get_selection_from_column(second_caret)) && (get_selection_from_line(first_caret) < get_selection_to_line(second_caret) || get_selection_from_column(first_caret) <= get_selection_to_column(second_caret))) {
				should_merge = true;
			}
			if (get_selection_to_line(first_caret) >= get_selection_from_line(second_caret) && get_selection_to_line(first_caret) <= get_selection_to_line(second_caret) && (get_selection_to_line(first_caret) > get_selection_from_line(second_caret) || get_selection_to_column(first_caret) >= get_selection_from_column(second_caret)) && (get_selection_to_line(first_caret) < get_selection_to_line(second_caret) || get_selection_to_column(first_caret) <= get_selection_to_column(second_caret))) {
				should_merge = true;
			}
			if (!should_merge) {
				continue;
			}
			
			int caret_to_save = first_caret;
			int caret_to_remove = second_caret;
			if (first_caret < second_caret) {
				caret_to_save = second_caret;
				caret_to_remove = first_caret;
			}
			int from_line = MIN(get_selection_from_line(caret_to_save), get_selection_from_line(caret_to_remove));
			int to_line = MAX(get_selection_to_line(caret_to_save), get_selection_to_line(caret_to_remove));
			int from_col = get_selection_from_column(caret_to_save);