mypy m2m iterator fix (#655)

* feat: add type hint for items in iterators for m2m relations

* chore: make flake8 happy
- rename some variables
- reorder some imports

* switch to typing.List

Co-authored-by: Benjamin Mollier <benjamin.mollier@meetap.de>
Co-authored-by: collerek <collerek@gmail.com>

ormar/models/mixins/save_mixin.py

@@ -79,9 +79,9 @@ class SavePrepareMixin(RelationMixin, AliasMixin):
 
     @classmethod
     def translate_enum_columns(cls, new_kwargs: dict) -> dict:
-        for k, v in new_kwargs.items():
-            if isinstance(v, Enum):
-                new_kwargs[k] = v.name
+        for key, value in new_kwargs.items():
+            if isinstance(value, Enum):
+                new_kwargs[key] = value.name
         return new_kwargs
 
     @classmethod