### 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
if (overtype_mode) {
													ts_caret.t_caret.position.y = TS->shaped_text_get_descent(rid);
													ts_caret.t_caret.size.y = caret_width;
												} else {
													ts_caret.t_caret.position.y = -TS->shaped_text_get_ascent(rid);
													ts_caret.t_caret.size.y = h;
												}
												ts_caret.t_caret.position += Vector2(char_margin + ofs_x, ofs_y);
												draw_rect(ts_caret.t_caret, theme_cache.caret_color, overtype_mode);
												if (ts_caret.l_caret != Rect2() && ts_caret.l_dir != ts_caret.t_dir) {
													
													ts_caret.l_caret.position += Vector2(char_margin + ofs_x, ofs_y);
													ts_caret.l_caret.size.x = caret_width;
													draw_rect(ts_caret.l_caret, theme_cache.caret_color);
													
													float d = (ts_caret.l_dir == TextServer::DIRECTION_LTR) ? 0.5 : -3;
													Rect2 trect = Rect2(ts_caret.l_caret.position.x + d * caret_width, ts_caret.l_caret.position.y + ts_caret.l_caret.size.y - caret_width, 3 * caret_width, caret_width);
													RenderingServer::get_singleton()->canvas_item_add_rect(ci, trect, theme_cache.caret_color);
												}
											} else { 
												if (gl_size > 0) {
													
													if (overtype_mode) {
														ts_caret.l_caret.position.y = TS->shaped_text_get_descent(rid);
														ts_caret.l_caret.size.y = caret_width;
													} else {
														ts_caret.l_caret.position.y = -TS->shaped_text_get_ascent(rid);
														ts_caret.l_caret.size.y = h;
													}
												} else if (overtype_mode) {