Add after-publish / after-package integration tests

[Bnaya]

Our current integration tests are running agains the source in the repo/build code,
via workspace and not real npm package (or tarballs)

In the real world, the code will run from inside npm package
It's very possible that something will get wrong in the packaging/publishing process (eg different paths)

We need to create an infra that will let us to run the same integration tests that we have against the to-be-published packages (using tarball or verdaccio local registry)

It's very important to also test the CLI inside each package

[gioragutt]

How about create an inner project with root-cause specified in package.json as "root-cause-core": "../../path/to/root/cause/in/the/repo"?