ci: use composite action, remove build steps for api and dashboard

[gulfaraz]

Describe your changes

1. Changed e2e workflow to run as a part of the CI workflow.
2. Added integration tests to the CI workflow.
3. Changed the default port to 3000 to make the current tests work.
   • Follow-up issue created [TASK] e2e test should use API to reset the database #1600

The next ones were needed to pass the integration tests,

4. Added a check to confirm if the directory exists before reading it.
5. Unlinked the integration tests from the seed data.
6. Added MWI, SSD, and flash-flood to example.env.

The next ones were needed to clean up warnings,

7. Upload the e2e dashboard log as a Github action artefact.
8. Added assertions to the integration tests.

Checklist before requesting a review

• I have performed a self-review of my code
• I have added tests wherever relevant
• I have made sure that all automated checks pass before requesting a review

Notes for the reviewer

1. I tried to update the tests to run without the API-service installation but it took too much effort so created the follow-up issue instead.
2. You can see the new workflow in action here.