[postcreate] properly set is_instance_of for bootstrap entities
Entities created before CWEType itself need the is/is_instance_of
relations created later. We were actually only inserting "is".
Closes #7656606.
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')