chore: Add kind integration test, fixes #41

[dhirajsb]

Description

Added kind integration test to build-image-pr.yaml workflow.
It creates a Kind cluster, deploys operator image built for the PR in the test cluster, and checks that it can create a model registry from sample model registry CR.
Fixes #41

How Has This Been Tested?

Tested GH action locally using act.

Merge criteria:

• The commits and have meaningful messages; the author will squash them after approval or will ask to merge with squash.
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has manually tested the changes and verified that the changes work

[tarilabs]

I've followed these steps to replicate locally:

kind create cluster
make docker-build

# locally, node chart-testing is not there, using default node
kind load docker-image quay.io/opendatahub/model-registry-operator:latest
make deploy
kubectl apply -k config/samples/
kubectl get mr

# monitoring pods:
kubectl get pods
# in my case: kubectl logs modelregistry-sample-5946c9799c-cvj5b

# after a while:
CONDITION="`kubectl get mr modelregistry-sample --output=jsonpath='{.status.conditions[?(@.type=="Available")].status}'`"
echo "Registry Available=${CONDITION}"

and output was eventually: Registry Available=True

[lampajr]

It works for me too and it looks great to me as first iteration but I would followup creating some e2e specific tests (e.g., using . "github.com/onsi/ginkgo", and "github.com/onsi/gomega") where we can add more tests if needed.

I mean I wouldn't keep test logic in the workflow itself, but lgtm as first bootstrap

[lampajr]

Sorry I missed this in previous analysis but I think it could be worth to add it

[lampajr]

lgtm, thanks @dhirajsb !