Migrate pod-init into operator chart, add testing

[nhudson]

This PR changes how the tembo-operator helm chart is installed. This is meant to improve end user experience using the operator helm chart. This PR changes the following:

• Operator chart now installs 2 main components (controller & pod-init) and 1 dependency component (CNPG) TEM-2033
• The chart installs pod-init and controller portions along with the CNPG operator as a dependency into the same namespace. TEM-2034
• Basic docs added to README
• CI/CD linting and testing using chart-testing
• Deprecate the tembo-pod-init helm chart.

[nhudson]

This is ready to start the review process. Things to note:

• I need to figure out if we need to generate a new GitHub Token to publish the charts

• More testing is needed to make sure we check the chart for version bumps if there are changes. Right now it checks what is in main but since it's not there yet, it fails the check. So for now it's commented out.

• I want to walk through the process of making sure our deployments are updated correctly before we merge this. The ArgoCD deployments will fail due to the number of changes in the charts.

[sjmiller609]

Looks great! I think we just need to look out for the upgrade concerns, so let's sync on that tomorrow and plan out how to roll it out

[sjmiller609]

These two steps look like they are doing the same thing

[nhudson]

The kind-action installs the kind binary into the step, the just start-kind sets up the cluster.

[sjmiller609]

Reminder - let's discuss cut-over plan for internal. Like since this is installed in another way internally, how to switch over our argo configs for this

[sjmiller609]

also for cut-over, we need to consider how to do this gracefully, I think just the workload going down and coming back works but we need to check on changing the helm ownership and ensuring safe cut over of the CRDs