CP-18294 rewrite unit test for mobility testing
CP-18294 rewrite unit test for mobility testing

This series of commits changes the way VM mobility is decided: the
relevant value are now picked up from VM_metrics and no longer from
platform flags. This must be reflected in the tests. The test suite now
populates the relevant fields in VM_metrics and tests the critical
VM operations.

Signed-off-by: Christian Lindig <4f88b50bc9dba63c9a7d9e208d4b3ac6f1a52800@citrix.com>

srowe/xen-api,srowe/xen-api,Frezzle/xen-api,srowe/xen-api,srowe/xen-api,euanh/xen-api,Frezzle/xen-api,euanh/xen-api,thomassa/xen-api,euanh/xen-api,Frezzle/xen-api,Frezzle/xen-api,euanh/xen-api,srowe/xen-api,thomassa/xen-api,thomassa/xen-api,thomassa/xen-api,Frezzle/xen-api,euanh/xen-api,thomassa/xen-api,thomassa/xen-api,euanh/xen-api