Remove VirtNUMAHostTopology.claim_test() method

Previous patches in this series remove the need for this method, so this
patch removes it.

We also remove the can_fit_instances() method which is now part of the
get_fitting_for_instance().

Change-Id: Ieb285bd7e06ea5c5bfc429ccad856272e147f885
Merge "Remove VirtNUMAHostTopology.claim_test() method"