Create a testing framework for future contributions about appsource

[aceamarco]

I'm leaving this ticket open since I won't be able to finish it before the end of my internship. In case others find this ticket at want to give it a try, here's what the current state of the enchancement-4 branch looks like.

Proposed Solution Design

The .github/workflows/ci.yaml has a job called test-e2e, heres what it does:

1. It starts a lightweight k3s cluster
2. It calls make e2e-test
3. make e2e-test calls hack/setup-argocd-env.sh which is a shell script that installs argocd onto the k3s cluster and creates the necessary argocd account and permissions for the controller to create applications.
4. It also installs the AppSource CRD and creates it's configmap
5. This next step is what needs to be done: the make e2e-test rule should then call go test on the pkg/controllers/suite_test.go file
6. This creates an instance of the AppSource manager then should start calling test functions that create/delete AppSource instances and configmaps from the tests/e2e/* folders that contain test appsource configmaps and appsource instances as described above in the initial proposal.
7. Every appsource instance created should be deleted before running files from a new test folder.