Use Poetry for dependency management

[psrok1]

trafficstars

Your checklist for this pull request

• [ ] I've read the contributing guideline.
• [ ] I've tested my changes by building and running the project, and testing changed functionality (if applicable)
• [ ] I've added automated tests for my change (if applicable, optional)
• [ ] I've updated documentation to reflect my change (if applicable)

What is the current behaviour?

What is the new behaviour?

Test plan

Closing issues

closes #issuenumber

[psrok1]

:thinking: Hmm, that Poetry works really nice

WIP:

• [ ] Fix test image
• [ ] Include plugins in build workflow
• [ ] Check if hot reload still works well in docker-compose-dev (should be OK because main package is installed by Poetry as "editable" .pth link)
• [ ] Create Poetry-based PyPi package publishing. Make sure that web artifacts are included.