### 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 (GDVIRTUAL_CALL(_handle_unicode_input, p_unicode, p_caret)) {
		return;
	}
	_handle_unicode_input_internal(p_unicode, p_caret);
}
void TextEdit::backspace(int p_caret) {
	if (GDVIRTUAL_CALL(_backspace, p_caret)) {
		return;
	}
	_backspace_internal(p_caret);
}
void TextEdit::cut(int p_caret) {