### 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
_scroll_down(delta);
		}
		h_scroll->set_value(h_scroll->get_value() + pan_gesture->get_delta().x * 100);
		if (v_scroll->get_value() != prev_v_scroll || h_scroll->get_value() != prev_h_scroll) {
			accept_event(); 
		}
		return;
	}
	Ref<InputEventMouseMotion> mm = p_gui_input;
	if (mm.is_valid()) {
		Vector2i mpos = mm->get_position();
		if (is_layout_rtl()) {
			mpos.x = get_size().x - mpos.x;
		}
		if (mm->get_button_mask().has_flag(MouseButtonMask::LEFT) && get_viewport()->gui_get_drag_data() == Variant()) { 
			_reset_caret_blink_timer();
			if (draw_minimap && !dragging_selection) {
				_update_minimap_drag();
			}
			if (!dragging_minimap) {
				switch (selecting_mode) {
					case SelectionMode::SELECTION_MODE_POINTER: {
						_update_selection_mode_pointer();
					} break;
					case SelectionMode::SELECTION_MODE_WORD: {
						_update_selection_mode_word();
					} break;
					case SelectionMode::SELECTION_MODE_LINE: {
						_update_selection_mode_line();
					} break;