### Godot version

4.1

### System information

Windows

### Issue description

Being able to have multiple cursors similarly to vscode is a great feature, however it's only possible to add carets, not remove them. By left clicking you can remove all extra cursors but you cannot remove a specific one so after selecting multiple lines a single missclick, you have to reselect them all again. Looking at the original pr there was a remove_caret function added so it would make sense to be able to remove carets when clicking again, like in vscode.

![image](https://github.com/godotengine/godot/assets/19669673/3867c00e-9faa-4429-9c6d-f2d6d3883044)


### Steps to reproduce

- Alt click to add multiple carets
- Alt click on the same position again
- Nothing happens

### 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);