### 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
Ref<InputEventKey> k = p_gui_input;
	if (k.is_valid()) {
		if (!k->is_pressed()) {
			if (alt_start && k->get_keycode() == Key::ALT) {
				alt_start = false;
				if ((alt_code > 0x31 && alt_code < 0xd800) || (alt_code > 0xdfff && alt_code <= 0x10ffff)) {
					handle_unicode_input(alt_code);
				}
				return true;
			}
			return false;
		}
		if (k->is_alt_pressed()) {
			if (!alt_start) {
				if (k->get_keycode() == Key::KP_ADD) {
					alt_start = true;
					alt_code = 0;
					return true;
				}
			} else {
				if (k->get_keycode() >= Key::KEY_0 && k->get_keycode() <= Key::KEY_9) {
					alt_code = alt_code << 4;
					alt_code += (uint32_t)(k->get_keycode() - Key::KEY_0);
				}
				if (k->get_keycode() >= Key::KP_0 && k->get_keycode() <= Key::KP_9) {