### 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
int col = 0;
	int colx = p_pos.x - (theme_cache.style_normal->get_margin(SIDE_LEFT) + gutters_width + gutter_padding);
	colx += first_visible_col;
	col = _get_char_pos_for_line(colx, row, wrap_index);
	if (get_line_wrapping_mode() != LineWrappingMode::LINE_WRAPPING_NONE && wrap_index < get_line_wrap_count(row)) {
		
		Vector<String> rows2 = get_line_wrapped_text(row);
		int row_end_col = 0;
		for (int i = 0; i < wrap_index + 1; i++) {
			row_end_col += rows2[i].length();
		}
		if (col >= row_end_col) {
			col -= 1;
		}
	}
	RID text_rid = text.get_line_data(row)->get_line_rid(wrap_index);
	if (is_layout_rtl()) {
		colx = TS->shaped_text_get_size(text_rid).x - colx;
	}
	col = TS->shaped_text_hit_test_position(text_rid, colx);
	if (!caret_mid_grapheme_enabled) {
		col = TS->shaped_text_closest_character_pos(text_rid, col);
	}
	return Point2i(col, row);
}
Point2i TextEdit::get_pos_at_line_column(int p_line, int p_column) const {
	Rect2i rect = get_rect_at_line_column(p_line, p_column);
	return rect.position.x == -1 ? rect.position : rect.position + Vector2i(0, get_line_height());
}
Rect2i TextEdit::get_rect_at_line_column(int p_line, int p_column) const {