* Instead of using Literal types, overload QuerySet.values_list in the plugin. Fixes#43.
- Add a couple of extra type checks that Django makes:
1) 'flat' and 'named' can't be used together.
2) 'flat' is not valid when values_list is called with more than one field.
* Determine better row types for values_list/values based on fields specified.
- In the case of values_list, we use a Row type with either a single primitive, Tuple, or NamedTuple.
- In the case of values, we use a TypedDict.
- In both cases, Any is used as a fallback for individual fields if those fields cannot be resolved.
A couple other fixes I made along the way:
- Don't create reverse relation for ForeignKeys with related_name='+'
- Don't skip creating other related managers in AddRelatedManagers if a dynamic value is encountered
for related_name parameter, or if the type cannot be determined.
* Fix for TypedDict so that they are considered anonymous.
* Clean up some comments.
* Implement making TypedDict anonymous in a way that doesn't crash sometimes.
* Fix flake8 errors.
* Remove even uglier hack about making TypedDict anonymous.
* Address review comments. Write a few better comments inside tests.
* Fix crash when running with mypyc ("interpreted classes cannot inherit from compiled") due to the way I extended TypedDictType.
- Implemented the hack in another way that works on mypyc.
- Added a couple extra tests of accessing 'id' / 'pk' via values_list.
* Fix flake8 errors.
* Support annotation expressions (use type Any) for TypedDicts row types returned by values_list.
- Bonus points: handle values_list gracefully (use type Any) where Tuples are returned
where some of the fields arguments are not string literals.
