QA: Drop dictionary support from qa_utils._GetName
QA: Drop dictionary support from qa_utils._GetName

This is no longer needed now that instance/node objects in QA have
attributes. Use a helper function instead to retrieve an entity's
identifying attribute.

Signed-off-by: Michael Hanselmann <68b67885ff74281219b4a4be33cc20fd45078d7c@google.com>
Reviewed-by: Bernardo Dal Seno <dcdd79c5479cb9d1329ec01d126f02cb045aa103@google.com>

andir/ganeti,ganeti/ganeti,apyrgio/ganeti,ganeti/ganeti,mbakke/ganeti,apyrgio/ganeti,ganeti-github-testing/ganeti-test-1,apyrgio/snf-ganeti,bitemyapp/ganeti,dimara/ganeti,andir/ganeti,leshchevds/ganeti,ganeti/ganeti,grnet/snf-ganeti,bitemyapp/ganeti,yiannist/ganeti,apyrgio/snf-ganeti,onponomarev/ganeti,leshchevds/ganeti,onponomarev/ganeti,grnet/snf-ganeti,yiannist/ganeti,dimara/ganeti,mbakke/ganeti,yiannist/ganeti,andir/ganeti,ganeti-github-testing/ganeti-test-1,mbakke/ganeti,leshchevds/ganeti