Also, removed EKG (I don't know how to make it work with WS)

This commit removes the need for a custom Opaleye fork by relying on
a newly-created `opaleye-textsearch` package following the design
outlined here:

https://github.com/tomjaguarpaw/haskell-opaleye/pull/563#issuecomment-1782794439

In my previous commit I had changed their implementation to use the
FromJSON/ToJSON istances, making sure those were backward compatible,
but apparently that wasn't the case.

After Fabien's changes, this needed amendment.

Also, fixed breadcrumbs to accept AppRoute.