### 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
if (Input::get_singleton()->is_mouse_button_pressed(MouseButton::LEFT) && get_selection_mode() != SelectionMode::SELECTION_MODE_NONE) {
		switch (get_selection_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;
			default: {
				break;
			}
		}
	} else {
		click_select_held->stop();
	}
}
void TextEdit::_update_selection_mode_pointer() {