webadmin: Created interdependence between profile actions

When creating multiple profiles from the Add/Edit Network dialog, the
backend actions were run using Frontend.RunMultipleAction() which
caused the validity of the actions to be checked
independently. However, the validity should be checked in an
interdependent manner (i.e. serially), because the completion of one
command can create conditions where another command is invalid
(e.g. if two commands try to create two vNIC profiles with the same
name). Solved by running Frontend.RunMultipleActions() instead.

Change-Id: I3d94298b0bd29be423d0b1b90c2174630de96092
Bug-Url: https://bugzilla.redhat.com/1031577
Signed-off-by: Lior Vernia <lvernia@redhat.com>