Django-dans-notifications

- Fixed `EmailThread` usage in `send_email` function

- Added type support!
- `py.typed`
- MyPy - config and CI step
- Added dependency for `Django Dans API Toolkit`
- https://pypi.org/project/django-dans-api-toolkit/
- Removed local code / serializers
- Updated response handler functions
- Improved logging and logger support
- No more `print`s either!
- Improved tests and coverage!
- Improved model tests
- Improved and added API tests
- All Python files now have tests
- 90% coverage!!!
- File structure cleaned up and consolidation

- Added support for lower Django versions

- Added support for Python 3.12 and Django 5.0
- Updated CI as well

- Lots of documentation clean up
- Packaging and PyPi clean up

- `NotificationEmail` handling and error improvements
- Removed generic `Exceptions` everywhere
- Code and License copyright updates