core: test negative flows for pattern-based name

Validate pattern-based names are not supported for VMs and Templates.

In addition, additional test was added to AddVmPoolWithVmsCommandTest
to validate that the validations pass when the pool's name is not
pattern-based as well.

Change-Id: I893a117a8eaa6abcb9d15abf599eb31426baab35
Signed-off-by: Arik Hadas <ahadas@redhat.com>