engine: add cpu profile to vm flow

* added to VmBase (vm/template)
* added to db layer (vm_static.cpu_profile_base)
* Added support to the follwing vm related commands:
add/update vm (and derivatives), add/update template, import vm/template.
* Backward compatibility: prior to 3.5 (cpu qos supported)- no check,
posterior to 3.5, no cpu-profile will be replaced iff there is a single
cpu profile in the cluster.

Change-Id: Ib01e4ab9e6d471d56fb972c8a4ee3e8dd8616db7
Signed-off-by: Gilad Chaplik <gchaplik@redhat.com>