Add Slick as a dependency
make JobQueueSender a trait so we can mock it
Write all we need for a Slick-backed DbBackend

This adds some Slick Tables and a Factory suite to insert into them.
Use Slick, not Squeryl, for ApiTokenFactory.

This skips a Transaction, shaving ~2ms off each request.
Create api.SearchController [refs #75540350]