### 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 (k->is_action("ui_text_newline_above", true)) {
			_new_line(false, true);
			accept_event();
			return;
		}
		if (k->is_action("ui_text_newline_blank", true)) {
			_new_line(false);
			accept_event();
			return;
		}
		if (k->is_action("ui_text_newline", true)) {
			_new_line();
			accept_event();
			return;
		}
		
		if (k->is_action("ui_text_backspace_all_to_left", true)) {
			_do_backspace(false, true);
			accept_event();
			return;
		}
		if (k->is_action("ui_text_backspace_word", true)) {
			_do_backspace(true);
			accept_event();
			return;
		}
		if (k->is_action("ui_text_backspace", true)) {
			_do_backspace();
			accept_event();
			return;