### 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);
		}
		
		Vector<String> rows = get_line_wrapped_text(get_caret_line(i));
		int wi = get_caret_wrap_index(i);
		int row_start_col = 0;
		for (int j = 0; j < wi; j++) {
			row_start_col += rows[j].length();
		}
		if (get_caret_column(i) == row_start_col || wi == 0) {
			
			int current_line_whitespace_len = get_first_non_whitespace_column(get_caret_line(i));
			if (get_caret_column(i) == current_line_whitespace_len) {
				set_caret_column(0, i == 0, i);
			} else {
				set_caret_column(current_line_whitespace_len, i == 0, i);
			}
		} else {
			set_caret_column(row_start_col, i == 0, i);
		}
		if (p_select) {
			_post_shift_selection(i);
		}