notification: use viewargs for notif_entity_updated instead of transaction_data
Now that notifications use separate sessions, they can't rely on the
original transaction_data being around, so pass the data through view
arguments instead, so the notification view knows what changed on
updated entities.
Closes #2936180
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')