[entity] Entity.related(): add a targettypes argument (closes #2957313)
This allows to restrict the entity types returned by the method
(passed to cw_related_rql).
When such an argument is given, no caching happens.
if 'same_as' in schema:
sync_schema_props_perms('same_as', syncperms=False)
sync_schema_props_perms('Bookmark', syncperms=False)