[dataimport] Add safety belt on "gen_rtype" in MetaGenerator, closes #3712892 Some cubes may well add to the META_RTYPES set, hence crashing the gen_<somecubemeta> call.

sync_schema_props_perms(('State', 'state_of', 'Workflow'), commit=False)
sync_schema_props_perms(('State', 'name', 'String'))