### 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);
		}
		Point2i next_line = get_next_visible_line_index_offset_from(get_caret_line(i), get_caret_wrap_index(i), -get_visible_line_count());
		int n_line = get_caret_line(i) - next_line.x + 1;
		set_caret_line(n_line, i == 0, false, next_line.y, i);
		if (p_select) {
			_post_shift_selection(i);
		}
	}
	merge_overlapping_carets();
}
void TextEdit::_move_caret_page_down(bool p_select) {