Add shell based tests for pac cli

[chmouel]

we can do a simple shell based test scenario like we have on tektoncd/cli https://github.com/tektoncd/cli/blob/main/test/e2e-tests.sh#L41 should be easy to setup and it would detect a bunch of error.

perhaps we can do as go directly too ? there is probably some framework for it (there is in rust afaik so should be one in go :D )

Originally posted by @chmouel in https://github.com/openshift-pipelines/pipelines-as-code/issues/711#issuecomment-1145588184