Server-side entries search

[tivac]

Currently search works against the entire set of entries in-memory, which is convenient but won't scale up to a large number of entries (See also, #133).

https://www.firebase.com/docs/web/guide/retrieving-data.html#section-queries describes how to query Firebase. Full-text search support on their end isn't great, but hopefully is good enough that we can filter by titles and show results to the user.

Results should be paginated using the same UI as #133.

[tivac]

@ctcleary This was fixed by #139 yes?

[ctcleary]

Not exactly.

We have a bandage over the problem because we search the most recent 100 entries by default (and we can really easily up that number if needed). But the search still functions precisely the same way, so if a user needs to "search all" because their target isn't in the most recent 100 entries, it'll still be really slow.

Figuring out how to do the server side search felt like a separate issue. I can bump this to the top of my current issues priority list if'n you like.

[tivac]

Ah, sure. I mis-remembered how your search impl from #139 worked. #138 is more important than this.