### 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_INDEX(p_line, text.size());
	ERR_FAIL_COND(p_wrap_index < 0);
	ERR_FAIL_COND(p_wrap_index > get_line_wrap_count(p_line));
	Point2i next_line = get_next_visible_line_index_offset_from(p_line, p_wrap_index, -get_visible_line_count() - 1);
	int first_line = p_line - next_line.x + 1;
	
	
	if (get_visible_line_count_in_range(0, p_line) < get_visible_line_count() + 1) {
		set_v_scroll(0);
		return;
	}
	set_v_scroll(get_scroll_pos_for_line(first_line, next_line.y) + _get_visible_lines_offset());
}
int TextEdit::get_last_full_visible_line() const {
	int first_vis_line = get_first_visible_line();
	int last_vis_line = 0;
	last_vis_line = first_vis_line + get_next_visible_line_index_offset_from(first_vis_line, first_visible_line_wrap_ofs, get_visible_line_count()).x - 1;
	last_vis_line = CLAMP(last_vis_line, 0, text.size() - 1);
	return last_vis_line;
}
int TextEdit::get_last_full_visible_line_wrap_index() const {