Censor NSFW posts in /search results

[TimJentzsch]

If a post is marked as NSFW in Blossom, its results in the /search command should be censored. The title should indicate that the post is NSFW and the context words (not the query itself) should be censored with * instead of the letters.

A pitfall of this is that the NSFW info is stored in the submission, not the transcription. So this could be more tricky than it seems at first glance.