### 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
ERR_FAIL_COND(p_caret > carets.size());
	if (!editable) {
		return;
	}
	start_action(EditAction::ACTION_TYPING);
	Vector<int> caret_edit_order = get_caret_index_edit_order();
	for (const int &i : caret_edit_order) {
		if (p_caret != -1 && p_caret != i) {
			continue;
		}
		
		if (overtype_mode && !has_selection(i)) {
			
			int cl = get_caret_line(i);
			int cc = get_caret_column(i);
			if (cc < get_line(cl).length()) {
				_remove_text(cl, cc, cl, cc + 1);
			}
		}
		const char32_t chr[2] = { (char32_t)p_unicode, 0 };
		insert_text_at_caret(chr, i);
	}
	end_action();
}
void TextEdit::_backspace_internal(int p_caret) {