Overhaul book search to take advantage of the featureset of Postgresql

[nanderv]

We have switched database engines with the switch to our dockerized setup. Since we now only support postgresql (and not sqlite, mysql, etc.), we can (and should) use features that make our lives easier.

As part of this, look at something like:

• accents
• spelling errors
• providing the results in some sort of order that makes sense
• Perhaps even make the user order
• If possible, show why something is in the result. This is not really feasible for books which have authors assigned to subworks

[nanderv]

This one requires a lot of further refinement