Allow api search to filter by book_id and chapter_id

[helderjsm]

In Api we should be able to search by book_id and or chapter_id to reduce the set of results.

Example search using book_id filtering:
http://localhost:6875/api/search?count=100&page=1&query=p{type:page}{book_id:5}
Example search using chapter_id filtering:
http://localhost:6875/api/search?count=100&page=1&query=p{type:page}{chapter_id:2}

[ssddanbrown]

Thanks for offering this PR @helderjsm.
Happy for such a feature to be implemented since it meets my main criteria for API additions (mirrors what we provide in the UI, and we provide chapter/book specific search).

I'm not too sure about adding them via filters though.
I think the use is fundamental enough for them to be considered as their own API endpoints.
So /api/search/book/{id}//api/search/chapter/{id}.
This way the type filtering can be hard-coded/limited instead of causing confusion in the need to apply them.