Set up CI/CD and add worker test

[lutangar]

Setup a test workflow, ex:
https://github.com/larriereguichet/alphacep-node-ffi-napi/actions/runs/1531317470

Setup a release workflow, ex:
https://github.com/larriereguichet/alphacep-node-ffi-napi/releases/tag/4.0.4

Then I recommend to:

1. Merge Setup CI via GitHub action ref-napi#1 and wait until the release process has succeeded.
2. Create an alphacep organisation on npm (if not already):
   https://www.npmjs.com/org/create
3. Generate a publish npm access token:
   https://www.npmjs.com/settings/nshmyrev/tokens
4. Add it as NPM_TOKEN to the repository secrets (or add an organization wide one, then you're done once and for all)
   https://github.com/alphacep/ref-napi/settings/secrets/actions
5. Push a new tag to publish the new release:

git tag -f 4.0.4
git push origin --tags