### 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 (get_viewport()->get_window_id() != DisplayServer::INVALID_WINDOW_ID && DisplayServer::get_singleton()->has_feature(DisplayServer::FEATURE_IME)) {
					DisplayServer::get_singleton()->window_set_ime_active(true, get_viewport()->get_window_id());
					Point2 pos = get_global_position() + get_caret_draw_pos();
					if (get_window()->get_embedder()) {
						pos += get_viewport()->get_popup_base_transform().get_origin();
					}
					DisplayServer::get_singleton()->window_set_ime_position(pos, get_viewport()->get_window_id());
				}
			}
		} break;
		case NOTIFICATION_FOCUS_ENTER: {
			if (caret_blink_enabled) {
				caret_blink_timer->start();
			} else {
				draw_caret = true;
			}
			if (get_viewport()->get_window_id() != DisplayServer::INVALID_WINDOW_ID && DisplayServer::get_singleton()->has_feature(DisplayServer::FEATURE_IME)) {
				DisplayServer::get_singleton()->window_set_ime_active(true, get_viewport()->get_window_id());
				Point2 pos = get_global_position() + get_caret_draw_pos();
				if (get_window()->get_embedder()) {
					pos += get_viewport()->get_popup_base_transform().get_origin();
				}
				DisplayServer::get_singleton()->window_set_ime_position(pos, get_viewport()->get_window_id());
			}
			if (DisplayServer::get_singleton()->has_feature(DisplayServer::FEATURE_VIRTUAL_KEYBOARD) && virtual_keyboard_enabled) {
				int caret_start = -1;
				int caret_end = -1;
				if (!has_selection(0)) {
					String full_text = _base_get_text(0, 0, get_caret_line(), get_caret_column());
					caret_start = full_text.length();