Add robot tests/integration tests like pytool-extensions

[spbrogan]

because basetools python applications are authored without python unit tests this project needs to validate at least as well as it did when it was integrated into the edk2 code tree.

To do that a robot framework based test can be used. See here for example: https://github.com/tianocore/edk2-pytool-extensions/tree/master/integration_test

This testing doesn't need to pass if for example you are making a breaking change, but by having this test the PR reviewers and author can confirm expected behavior.

[spbrogan]

Request was to make this a required check to pass. Maintainer/admin could override in the rare case of a breaking change.

[Javagedes]

The platform build file's for EmulatorPkg, OvmfPkg, and ArmVirtPkg do not have the logic to detect and decide which of version of BaseTools to use (in-tree or pypi) like the CISetting files do. I've added that logic in a branch and will work on getting it into EDK2.

Until then, I've finished the integration tests and will add a PR so that the pipelines can be verified, but they will continue to run with the in-tree pytools until the platform build files are updated as I mentioned above.