### 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_caret, carets.size(), -1);
	ERR_FAIL_COND_V(!has_selection(p_caret), -1);
	return carets[p_caret].selection.selecting_line;
}
int TextEdit::get_selection_column(int p_caret) const {
	ERR_FAIL_INDEX_V(p_caret, carets.size(), -1);
	ERR_FAIL_COND_V(!has_selection(p_caret), -1);
	return carets[p_caret].selection.selecting_column;
}
int TextEdit::get_selection_from_line(int p_caret) const {
	ERR_FAIL_INDEX_V(p_caret, carets.size(), -1);
	ERR_FAIL_COND_V(!has_selection(p_caret), -1);
	return carets[p_caret].selection.from_line;
}
int TextEdit::get_selection_from_column(int p_caret) const {