[predicates] fix paginated_rset when the class has no page_size_property Fixes test failure introduced by 70733b2dfd2a, which assumed paginated_rset would only be called on a class with a page_size_property attribute.

[repository] drop usage of no more necessary eschema_eid function since the previous cset, we are guaranteed that repository's entity schema will have their eid attribute properly set, so we don't have anymore to check everytime if some entity schema's .eid attributes is set or not (and retrieve it if not). Related to #10450092

[repository] set .eid on eschema when schema is loaded from the filesystem enforcing the contract that a repository's schema should have .eid attribute of entity schema set to the eid of the entity used to serialize them in the db. Before this cset, this was not true during tests or for some c-c commands where 'quick_start' is set (eg db-restore, i18ncube...). The change in server __init__ makes this assumption true during instance creation: the serializing code was actually setting eid on schema object, but a reference to a previously built schema was given instead of the one for the latest created repository. Closes #10450092

[dataimport] simplify SQLGenSourceWrapper.add_info At this point 'CWSource' is a thing (we're not in the middle of a migration), and source.eid won't be None (we read it from the db)