Remove job_access class.

This code is unused. The JobsController allows unauthenticated access, and does not use any of the valide_access methods from model_controller, so the JobsAccess is not needed.
Remove authentication logic from ShardDomainAccess

All authentication logic happens during the check_authentication method
-- before this access class is ever used. Because the desired behavior
is that any authenticated user can perform the read action on the class,
the access class does need to check any user permissions and only needs
to return true.
Refactor and backfill some tests