Updates to support custom tokenizer and improved RTL display

[jacobwegner]

This PR lands a few things back to the feature/ibnsaid branch:

• Heroku / GitHub Actions fixes
• Improved RTL support in the interlinear widget
• Support for custom tokenizers and a stub file demonstrating them

Verified locally and in Codespaces:

/reader/urn:cts:arabicLit:amedsaid1831.dw042.perseus-ara1:1?mode=interlinear

To review these changes, you'll want to check out the ibnsaid-tokenizer branch in Codespaces and then:

• Update frontend and backend dependencies:

# from backend shell
pip uninstall -y scaife-viewer-atlas
pip install "scaife-viewer-atlas @https://github.com/scaife-viewer/backend/archive/552ee49c150439f96bab9f40b46e822ac452f4d0.zip#subdirectory=atlas"

# from frontend shell
yarn install

• Re-ingest content:

  # from backend shell
  python manage.py prepare_atlas_db --force

[jacobwegner]

@jchill-git I've done this as a PR so you can verify the changes before we merge into your feature branch.

If things are working here, please go ahead and approve and merge this branch.

If things aren't working, please let me know...happy to try and troubleshoot with you!