### 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
} else {
			if (mb->get_button_index() == MouseButton::LEFT) {
				if (selection_drag_attempt && is_mouse_over_selection()) {
					remove_secondary_carets();
					Point2i pos = get_line_column_at_pos(get_local_mouse_pos());
					set_caret_line(pos.y, false, true, 0, 0);
					set_caret_column(pos.x, true, 0);
					deselect();
				}
				dragging_minimap = false;
				dragging_selection = false;
				can_drag_minimap = false;
				click_select_held->stop();
				if (!drag_action) {
					selection_drag_attempt = false;
				}
				if (DisplayServer::get_singleton()->has_feature(DisplayServer::FEATURE_CLIPBOARD_PRIMARY)) {
					DisplayServer::get_singleton()->clipboard_set_primary(get_selected_text());
				}
			}
			
			notification(NOTIFICATION_FOCUS_ENTER);
		}
	}
	const Ref<InputEventPanGesture> pan_gesture = p_gui_input;
	if (pan_gesture.is_valid()) {
		const real_t delta = pan_gesture->get_delta().y;
		if (delta < 0) {
			_scroll_up(-delta);
		} else {