Bug when trying to overload natural_key_field_names with nested related fields

[jathanism]

Environment

• Nautobot version (Docker tag too if applicable): 2.0.0b1
• Python version: 3.9
• Database platform, version: n/a
• Middleware(s): n/a

Steps to Reproduce

1. Replace IPAddress.natural_key_field_names with ["parent__namespace__name", "host"]
2. Get an instance of an IPAddress
3. Attempt to call IPAddress.objects.get_by_natural_key(*instance.natural_key()) to perform a symmetric lookup

Expected Behavior

Should return the same instance that was used to make the call.

Observed Behavior

A FieldDoesNotExist error is raised:

In [1]: instance = IPAddress.objects.first()

In [2]: instance.natural_key()
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
File ~/Library/Caches/pypoetry/virtualenvs/nautobot-b2ttWva6-py3.10/lib/python3.10/site-packages/django/db/models/options.py:608, in Options.get_field(self, field_name)
    605 try:
    606     # Retrieve field instance by name from cached or just-computed
    607     # field map.
--> 608     return self.fields_map[field_name]
    609 except KeyError:

KeyError: 'parent__namespace__name'

During handling of the above exception, another exception occurred:

FieldDoesNotExist                         Traceback (most recent call last)
Cell In[2], line 1
----> 1 instance.natural_key()

File ~/sandbox/src/nautobot/nautobot/core/models/__init__.py:90, in BaseModel.natural_key(self)
     83 """
     84 Smarter default implementation of natural key construction.
     85
     86 1. Handles nullable foreign keys (https://github.com/wq/django-natural-keys/issues/18)
     87 2. Handles variadic natural-keys (e.g. Location model - [name, parent__name, parent__parent__name, ...].)
     88 """
     89 vals = []
---> 90 for lookups in [lookup.split("__") for lookup in self.natural_key_field_lookups]:
     91     val = self
     92     for lookup in lookups:

File ~/Library/Caches/pypoetry/virtualenvs/nautobot-b2ttWva6-py3.10/lib/python3.10/site-packages/django/utils/functional.py:61, in classproperty.__get__(self, instance, cls)
     60 def __get__(self, instance, cls=None):
---> 61     return self.fget(cls)

File ~/sandbox/src/nautobot/nautobot/core/models/__init__.py:156, in BaseModel.natural_key_field_lookups(cls)
    154 natural_key_field_lookups = []
    155 for field_name in natural_key_field_names:
--> 156     field = cls._meta.get_field(field_name)
    157     if getattr(field, "remote_field", None) is None:
    158         # Not a related field, so the field name is the field lookup
    159         natural_key_field_lookups.append(field_name)

File ~/Library/Caches/pypoetry/virtualenvs/nautobot-b2ttWva6-py3.10/lib/python3.10/site-packages/django/db/models/options.py:610, in Options.get_field(self, field_name)
    608     return self.fields_map[field_name]
    609 except KeyError:
--> 610     raise FieldDoesNotExist("%s has no field named '%s'" % (self.object_name, field_name))

FieldDoesNotExist: IPAddress has no field named 'parent__namespace__name'

Additionally if you instead try to overload natural_key_field_lookups (vs. natural_key_field_names), the call to instance.natural_key() succeeds, but calls to IPAddress.objects.get_by_natural_key() is out of phase and results in a DoesNotExist error:

In [1]: instance = IPAddress.objects.first()

In [2]: instance.natural_key()
Out[2]: ['Global', '10.0.0.0']

In [3]: IPAddress.objects.get_by_natural_key(*instance.natural_key())
---------------------------------------------------------------------------
DoesNotExist                              Traceback (most recent call last)
File ~/sandbox/src/nautobot/nautobot/core/models/managers.py:42, in BaseManager.get_by_natural_key(self, *args)
     41 try:
---> 42     kwargs[field_name] = related_model.objects.get_by_natural_key(*related_values)
     43 except related_model.DoesNotExist as exc:

File ~/sandbox/src/nautobot/nautobot/core/models/managers.py:46, in BaseManager.get_by_natural_key(self, *args)
     44         raise self.model.DoesNotExist() from exc
---> 46 return self.get(**kwargs)

File ~/Library/Caches/pypoetry/virtualenvs/nautobot-b2ttWva6-py3.10/lib/python3.10/site-packages/django/db/models/manager.py:85, in BaseManager._get_queryset_methods.<locals>.create_method.<locals>.manager_method(self, *args, **kwargs)
     84 def manager_method(self, *args, **kwargs):
---> 85     return getattr(self.get_queryset(), name)(*args, **kwargs)

File ~/sandbox/src/nautobot/nautobot/ipam/querysets.py:261, in PrefixQuerySet.get(self, prefix, *args, **kwargs)
    260     kwargs["broadcast"] = last_ip
--> 261 return super().get(*args, **kwargs)

File ~/Library/Caches/pypoetry/virtualenvs/nautobot-b2ttWva6-py3.10/lib/python3.10/site-packages/django/db/models/query.py:435, in QuerySet.get(self, *args, **kwargs)
    434 if not num:
--> 435     raise self.model.DoesNotExist(
    436         "%s matching query does not exist." %
    437         self.model._meta.object_name
    438     )
    439 raise self.model.MultipleObjectsReturned(
    440     'get() returned more than one %s -- it returned %s!' % (
    441         self.model._meta.object_name,
    442         num if not limit or num < limit else 'more than %s' % (limit - 1),
    443     )
    444 )

DoesNotExist: Prefix matching query does not exist.

The above exception was the direct cause of the following exception:

DoesNotExist                              Traceback (most recent call last)
Cell In[3], line 1
----> 1 IPAddress.objects.get_by_natural_key(*instance.natural_key())

File ~/sandbox/src/nautobot/nautobot/core/models/managers.py:44, in BaseManager.get_by_natural_key(self, *args)
     42         kwargs[field_name] = related_model.objects.get_by_natural_key(*related_values)
     43     except related_model.DoesNotExist as exc:
---> 44         raise self.model.DoesNotExist() from exc
     46 return self.get(**kwargs)

DoesNotExist:

[glennmatthews]

Closed by #3903.