DRAFT: 136 fix branch reversion

[arthanson]

Fixes: #136

Note: This requires the NetBox change netbox-community/netbox#19680 to work correctly.

This was caused by several issues:

1. In NetBox the ordering of ChangeLog items when there were GenericRelations between them was out-of-order. This is fixed in the NetBox PR above.
2. Following this - the deserialize_object was using self.prechange_data, but this was picking up internal fields like _path on cabled objects, changed to use self.prechange_data_clean to remove these fields.
3. Also - the clean method in Cable uses the GenericForeign key reference, the deserializer sets the object_id and content_type but the actual content_object was None. This goes through and fixes these back up.