[server] change order of entities table modification vs entity creation/deletion In order to have a foreign key referencing the entities table, the insertion into entities must happen first, and the deletion must happen last. For the deletion case, this means we need to: 1. delete all relations (cascade) 2. delete the entities themselves 3. delete the corresponding lines from the entities table This means the _delete_info{,_multi} methods can't keep doing 1 and 3. Thankfully the "public" delete_info method appears to be unused, so drop it. Related to #4846892.

change_attribute_type('CWCache', 'timestamp', 'TZDatetime')
change_attribute_type('CWUser', 'last_login_time', 'TZDatetime')
change_attribute_type('CWSource', 'latest_retrieval', 'TZDatetime')
drop_attribute('CWSource', 'synchronizing')
add_attribute('CWSource', 'in_synchronization')