electric-db: handle stringSort and locale in orderBy

[kevin-dp]

Currently, when an orderBy clause is pushed down to the Electric DB collection, it does not handle the stringSort and locale options. If these options are used that means that we will get unexpected results from the subsets that are loaded from PG. We need to handle these options properly. cc @samwillis

[kevin-dp]

Closing this as we introduced collection-wide locale configurations in #762. The idea is that each application would configure the app such that the locale options match the backend's locale.