Add unit test workflow

[pawelirh]

Changes

• Implemented testing workflow
• Fully tested on the panteher_utils package ✅
• Runner needs to be further improved to handle successfully all unit tests

❗ SQUASH COMMITS! ❗

[github-actions]

Test coverage of modified packages:
lines......: 99.4% (328 of 330 lines)
functions..: 100.0% (130 of 130 functions)
branches...: 34.4% (400 of 1162 branches)

[delihus]

Please describe the workflow in the readme file. Maybe add some nice workflow status badge?
https://docs.github.com/en/actions/monitoring-and-troubleshooting-workflows/adding-a-workflow-status-badge

[pawelirh]

Regarding both comments

I'd wait with the readme update and badge until the tests are fully functional and pass to avoid always having a red badge.

As for the information that tests are run on hardware I'd see that info somewhere near/on the badge in readme. I'm not sure about the proposed filename since we don't need to distinguish between "hardware" and "non-hardware"(GitHub-hosted). What do you think, is it a good option in your opinion?