webadmin: Move enums to localized file

The MigrationSupport enums ware located in the wrong file and so could
not be localized.
Moved the enums to the correct file

Deleted redundant method from UnitVmModel

Change-Id: I87edacf6b3aa2180f1e8721b8f342ca04a648e3f
Signed-off-by: Ofri Masad <omasad@redhat.com>