webadmin: move-copy disks - inactive domains indication

Move/Copy disks dialogs:
* Added a tool-tip for source storage domains label/select-box
  (indicating unavailable source storage domains).
* Added a tool-tip for target storage select-box
  (indicating unavailable target storage domains /
   missing template on target storage domains).
* Ensured that only disks that can be moved/copied
  (with regard to active source/target storage domain availability)
  are sent to the backend.
* Display a warning when some of the disks cannot be moved/copied.

Change-Id: Id1c17bbcdfa9c2358a17b297ef99a94254f68132
Bug-Url: https://bugzilla.redhat.com/880917
Bug-Url: https://bugzilla.redhat.com/907120
Signed-off-by: Daniel Erez <derez@redhat.com>