464 implement frontend javascript testing

[sbland]

Description

Some tidying up of the frontend node code related to #529

Fixes #529

Type of change

• Documentation (non-breaking change that adds or improves the documentation)
• New feature (non-breaking change which adds functionality)
• Optimization (non-breaking, back-end change that speeds up the code)
• Technical work (non-breaking, change which is work as part of a new feature)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (whatever its nature)

Key checklist

• All tests pass (eg. python -m pytest)
• The documentation builds and looks OK (eg. mkdocs serve)
• Pre-commit hooks run successfully (eg. pre-commit run --all-files)

Further checks

• Code is commented, particularly in hard-to-understand areas
• Tests added or an issue has been opened to tackle that in the future. (Indicate issue here: # (issue))

[sbland]

Fixes #464

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[sbland]

@AdrianDAlessandro I moved the node documentation to a separate README.md inside the node directory. This seems to have broken the mkdocs build. I tried looking through the code and docs but I can't see how to add this file.

[github-actions]

🚫 [linkspector] _{reported by reviewdog 🐶}
Cannot reach https://github.com/direct-framework/direct-webapp/blob/main/node/README.md Status: 404

[sbland]

@AdrianDAlessandro FYI I've rebased this onto the main branch.