Remove dependency on six

[oddstr13]

Remove all usage of six and kodi_six.

• [ ] Squash commits?
• [ ] Add commits to ignore?

A few changes have potential of maybe being functional, but I don't think they are in modern python/kodi versions.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 64.35644% with 36 lines in your changes missing coverage. Please review.

Project coverage is 21.50%. Comparing base (1910de8) to head (876e940). Report is 12 commits behind head on master.

Files	Patch %	Lines
jellyfin_kodi/library.py	20.00%	12 Missing :warning:
jellyfin_kodi/entrypoint/default.py	0.00%	7 Missing :warning:
jellyfin_kodi/helper/utils.py	66.66%	2 Missing and 1 partial :warning:
jellyfin_kodi/database/__init__.py	50.00%	2 Missing :warning:
jellyfin_kodi/jellyfin/http.py	0.00%	2 Missing :warning:
jellyfin_kodi/objects/obj.py	50.00%	2 Missing :warning:
jellyfin_kodi/dialogs/context.py	66.66%	1 Missing :warning:
jellyfin_kodi/dialogs/loginmanual.py	50.00%	1 Missing :warning:
jellyfin_kodi/dialogs/serverconnect.py	66.66%	1 Missing :warning:
jellyfin_kodi/dialogs/servermanual.py	50.00%	1 Missing :warning:
... and 4 more

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #880 +/- ## ======================================= Coverage 21.49% 21.50% ======================================= Files 63 63 Lines 8626 8632 +6 Branches 1586 1585 -1 ======================================= + Hits 1854 1856 +2 - Misses 6748 6755 +7 + Partials 24 21 -3 ```

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[sonarcloud[bot]]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
1.3% Duplication on New Code

See analysis details on SonarCloud

[oddstr13]

The internal restart/reload addon function seems to be broken, but I don't think that is caused by this PR. Fixing it is out of scope for this PR in any case.