### 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
switch (p_what) {
		case NOTIFICATION_POSTINITIALIZE: {
			_update_caches();
		} break;
		case NOTIFICATION_ENTER_TREE: {
			_update_caches();
			if (caret_pos_dirty) {
				MessageQueue::get_singleton()->push_call(this, "_emit_caret_changed");
			}
			if (text_changed_dirty) {
				MessageQueue::get_singleton()->push_call(this, "_text_changed_emit");
			}
			_update_wrap_at_column(true);
		} break;
		case NOTIFICATION_RESIZED: {
			_update_scrollbars();
			_update_wrap_at_column();
		} break;
		case NOTIFICATION_VISIBILITY_CHANGED: {
			if (is_visible()) {
				call_deferred(SNAME("_update_scrollbars"));
				call_deferred(SNAME("_update_wrap_at_column"));
			}
		} break;
		case NOTIFICATION_LAYOUT_DIRECTION_CHANGED:
		case NOTIFICATION_TRANSLATION_CHANGED:
		case NOTIFICATION_THEME_CHANGED: {
			if (is_inside_tree()) {
				_update_caches();