- Added 2 new tests: ndb_pfs_tables and metadata_sync_pfs
- The former serves as a basic test for all performance schema tables
  added by the ndbcluster plugin. The metadata_sync_pfs test covers
  cases specific to the auto sync functionality and the 2 new tables
  added
- Modified existing test metadata_sync_debug to query the
  ndb_sync_excluded_objects table

Change-Id: I4c6eb122894c574cb5b2fa8b4921e6589eba80c6