What does this MR do?

This hides a note's preview if it's the same note that's already quoted

I do not particularly love this solution, but it is simple and effective; I can't find another reliable way to determine if a link goes to a local note of the given id, apart from fetching the link

The reason this is even needed is that local notes don't have a url or uri value, so the URL extracted from the quoting note's text is not filtered out by the computation of urls