build: upgrade FOCA

[uniqueg]

• Upgrade FOCA to latest version (>=0.12.1), also resolving startup errors (#33) and Celery app registration (#42)
  • Update requirements.txt and requirements_dev.txt
  • Update Dockerfile
• Some work towards improved consistency with elixir-cloud-aai/proTES, partly necessitated due to the FOCA upgrade:
  • Harmonize setup.py
  • Add pro_wes/version.py
  • Harmonize all app entry points: pro_wes/app.py, pro_wes/celery_worker.py (renamed from pro_wes/worker.py), pro_wes/gunicorn.py and pro_wes/wsgi.py
  • Lift strict dependency version requirements (all future minor and patch versions supported)
  • Some automatic reformatting by black
  • Add or harmonize some package docstrings
• CI workflow upgrades
  • Fix integration test in CI pipeline
  • Add linting job (flake8 only)
  • Add publishing job
• Remove debugging artifacts

Fixes #60 Fixes #33 Fixes #42