Nilspodlib

- Removed upper version bounds to avoid version conflicts during installation

Changed

- Synchronisation related error messages have been improved massively and now provide tips on how to debug and resolve
common problems
- All sync related issues now raise a `SynchronisationError` instead of other generic errors.
Note, that this breaks the workaround detailed [here](https://github.com/mad-lab-fau/NilsPodLib/issues/15) for one of
the common issues. Instead of catching a `ValueError`, you should now catch a `SynchronisationError`.
- All Validation related errors now throw a `SessionValidationError`.

Bugfixes
- Fixed bug originated due to switching from `distutils.StrictVersion` to `packaging.version.Version`

!!! Dropped Python 3.7 support !!!

Changed

- All usages of `distuils.StrictVersion` are replaced with `packaging.version.Version`, as the former is deprecated.
- `Self` type is used whenever a method returns itself (or a copy). A bunch of other typing issues were fixed while
doing that

Packaging

- Dropped Python 3.7 support
- Now committing lock file
- Switched to `poethepoet` from doit
- Updated readthedocs config to not require a seperate requirements.txt

Added

- added `force_version` parameter to `Session` to force specific firmware versions for dev firmwares.

Changed

- Version checks within the legacy converter now ignore dev builds. If you are using a dev build, you are on your own!