### 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
for (int i = 0; i < carets.size(); i++) {
		if (p_select) {
			_pre_shift_selection(i);
		} else {
			deselect(i);
		}
		int cur_wrap_index = get_caret_wrap_index(i);
		if (cur_wrap_index < get_line_wrap_count(get_caret_line(i))) {
			set_caret_line(get_caret_line(i), i == 0, false, cur_wrap_index + 1, i);
		} else if (get_caret_line(i) == get_last_unhidden_line()) {
			set_caret_column(text[get_caret_line(i)].length());
		} else {
			int new_line = get_caret_line(i) + get_next_visible_line_offset_from(CLAMP(get_caret_line(i) + 1, 0, text.size() - 1), 1);
			set_caret_line(new_line, i == 0, false, 0, i);
		}
		if (p_select) {
			_post_shift_selection(i);
		}
	}
	merge_overlapping_carets();
}
void TextEdit::_move_caret_to_line_start(bool p_select) {