Engine: Fixes #3325: Initial fixes to get content search UI working.
Engine: fixes #3318: Red Hat Repositories initial conversion

This commit contains initial changes to support the Red Hat Repositories
page in the UI.

It also has some changes for the 'old tupane' version of
providers/products/repos.  Although we'll be removing that in the
future, went ahead and updated the files since was in there anyway.
Engine: fixes #3314, 3317: Red Hat Subscriptions initial conversion
Engine: Fixes #3480: Correction to path for dashboard redirect.
Engine: engine-users - fixes #3331
Engine: Fixes #3326, 3327: Changesets & Changeset History initial conversion

Modifications to UI for Changesets and Changeset History to function
within an engine.
Engine: Dashboard: few fixes for syncs, content views and promotions
Engine: Authorization: use ::User vs User

Updating references to User to explicitly point to the core
user (::User)
Engine: fixes #3332: Roles initial conversion

This is the initial conversion of the katello roles ui to work
within the engine.  This includes CRUD actions for roles
and permissions.
Engine: fixes #3479 - db:seeds fails if readonly role exists and is locked but role has no permissions