Port to Flask

[Gouvernathor]

Work in progress. Fixes #154.

• Ports the system from PHP to Flask
• Allows for up to Python 3.11
• Uses the parliamentarch module as a backend
  • Obsoletes newarch.py and the changes thereto
  • Implements the Revamp layout
• Simplifies redirects
• Makes the repo way easier to deploy by anyone
• Also there's a favicon now. You're welcome.

TODO:

• Testing needs to be done, a lot.
• Move US JS code away in a dedicated JS file (maybe in a separate PR).
  • stop importing the parliamentarch js into the other pages - name collisions yield incorrect errors when a JS import fails
  • done in #161
• Implement OAuth (using the cool Toolforge tutorials)
  • cleanup the index, auth and response PHP files when done
  • done in #161
• (optional) have the header bar be blue in prod, green on beta, and brown on local
  • that will be done separately, as it's not directly related

The commands required to run the site from Toolforge will change (slightly), and the path where the cleanup job will intervene will change as well.