### 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_V(p_line, text.size(), 0);
	p_wrap_index = MIN(p_wrap_index, text.get_line_data(p_line)->get_line_count() - 1);
	RID text_rid = text.get_line_data(p_line)->get_line_rid(p_wrap_index);
	if (is_layout_rtl()) {
		p_px = TS->shaped_text_get_size(text_rid).x - p_px;
	}
	int ofs = TS->shaped_text_hit_test_position(text_rid, p_px);
	if (!caret_mid_grapheme_enabled) {
		ofs = TS->shaped_text_closest_character_pos(text_rid, ofs);
	}
	return ofs;
}
void TextEdit::_emit_caret_changed() {
	emit_signal(SNAME("caret_changed"));
	caret_pos_dirty = false;
	caret_index_edit_dirty = true;
}
void TextEdit::_reset_caret_blink_timer() {
	if (!caret_blink_enabled) {
		return;
	}
	draw_caret = true;
	if (has_focus()) {
		caret_blink_timer->stop();
		caret_blink_timer->start();
		queue_redraw();
	}
}
void TextEdit::_toggle_draw_caret() {