Simplify pseudo reference types, decouple from `MProxy`.

- test users -> userN
- test user groups -> groupOMN
- test auth -> auth

Changed the config mechanism to delay validation until all data is read, streamlined configuration logic, and improved use of pydantic validators.

Changelog: Changed

Changed the configuration loading logic to support partial updates that are validated only once the full configuration is loaded.

Changelog: Changed

Changelog: Added

Changelog: Added

Remove old workflow section: definitions, parsing, normalization.

Changelog: Added

Changelog: Added

There was an issue with recreating parser instances, which only
appeared when the reuser_parser process setting was set to
false. The fix now allows to correctly recreate parser instances.

Changelog: Fixed

Changelog: Changed

Use pydantic to create formal models with documentation for all
configuration items. From these models a documentation page
is generated as a reference.

Changelog: added

- switching to `pyproject.toml` for the python setup process [PEP 621](https://peps.python.org/pep-0621/)
- storing gui artifacts to avoid cyclic dependency
- using dynamic version based the git status using [setuptools-scm](https://pypi.org/project/setuptools-scm/)
- fix python pacakge conflicts by using [pip-tools](https://github.com/jazzband/pip-tools)
- Multi stage docker build  
- CI/CD: switching to the built image for testing
- cleanup refactoring (`.gitignore`, `MANIFEST.in`, `scripts`, etc.)