Validate and test packaged version of libraries

[jelbourn]

We currently have no automated tests for the actual npm package we produce. We should, at the very least, run our e2e tests against the real packages.

It would additionally be good to test the components against an Angular CLI application. It might be best, then, to change our e2e app to be an Angular CLI application.

Some other possibilities worth discussion:

• [ ] Creating a general angular-package-validator tool that we could use for all Angular-related projects.
• [ ] Clone and run the tests for angular.io and/or material.angular.io with the packages

Other related checks

• Ensure that the release doesn't include cdk/testing or material/testing

Open to other ideas here.

cc @josephperrott

[devversion]

I think this is partially done by the new integration test rule we added as part of dev-infra.

We just need to increase the scenario coverage much more