ci: setup github actions for testing, code formatting & linting the frontend

[khaledosman]

What's changing

Adds new github actions to

1. Check code formatting on the frontend with prettier
2. Lint frontend code using eslint
3. Run unit tests on the frontend
4. Run e2e test on the frontend (cache and install playwright browsers)

How to test it

Steps to test the changes:

1. Check the new pipelines attached to this PR

I already...

• Tested the changes in a working environment to ensure they work as expected
• Added some tests for any new functionality
• Updated the documentation (both comments in code and product documentation under /docs)
• Checked if a (backend) DB migration step was required and included it if required