possibility to search for signs with non-manual video available

[uklomp]

I'd like to have the option to search for glosses with a video in the 'videos with non-manual elements' panel available. Suggestion: with the extended search, under "search by publication status and notes", there's the 'other media' row. Now there is just the 'yes' and 'no', and I think it is for video's under 'other media'? Which we don't use at the moment but maybe is used by other people or in the future. Maybe we can implement the NME option here, e.g. a 'yes: NME' and 'yes: other media' and 'no'?

[I'll make a new issue for the following thought: Now that I'm thinking about it, it would also be good if we could search for glosses with an annotated sentence here. I know this is a separate search function now, but maybe it could be put together.]