userportal,webadmin: frontend refactor phase 2

- Marked all static methods on Frontend deprecated.
- Changed most static calls to Fronted to either getInstace().X
or had frontend injected and make regular calls.
- All Frontend static query/action/login/logout methods now have
an equivalent regular method.
- Implemented an automatic retry mechanism for query operations.
- Code now automatically ignores duplicate query requests. Duplicates
are ignored while running, as well as while pending.
- Put GenericApiGWTServiceAsync behind a communication provider interface
so it becomes easier to swap out in the future.
- Abstracted queries and actions into operations which are processed by
the operation processor.

Change-Id: Id19491b8fd4f30ad3a88790eaad664d679b35e22
Signed-off-by: Alexander Wels <awels@redhat.com>