Add integration tests to to CI pipeline (Playwright)

[marco-souza]

To avoid publishing a broken version of our app, we need to run integration tests before deploying to production.

I suggest implementing integration tests to validate our main workflows. This also simplifies the migration work for the next latest version.

Tasks:

• [x] setup playwright for our site
  • [x] run it locally
• [x] setup GitHub Actions
• [x] Implement integration tests

References:

• https://playwright.dev/docs/ci-intro