Configured DevContainer for Python Client; Fixed HF Unittest; Integrated Unittests into VSCode; Quality of Life

[TheMrSheldon]

This PR provides some general fixes and improvements to the repo and the VSCode integration:

• Updated the dev container config for developing the Python Client (including Docker integration with the docker host)
• Moved all dev container related stuff (especially .devfiles) into .devcontainer to clean up the project root
• Integrated python unittests into VSCode (this also required configuring a multiroot workspace)
• Consolidated all unittest actions into test.yaml
• Removed django static files (unused and added untested paths)
• Removed _default_hf_home_in_tira_host