webadmin: Alert/Event/Task footer fix

- The massive GIN update patch caused the events/alerts/tasks
  to not update properly, this patch fixes the problem. The problem
  was that the initialization flag was stored in the model which is
  a singleton, so the second provider that uses the model would not
  initialize its handlers. We changed the flag to be stored in the
  provider instead.
- Removed the *FirstRowModelProvider as they are simply not needed.

Change-Id: I9083319d000e66404d531c9576a28e184979f485
Signed-off-by: Alexander Wels <awels@redhat.com>