Upgrade helm and clean up generated code/files under config

[unmarshall]

How to categorize this issue?

/area quality
/kind cleanup

What would you like to be added:

• Upgrade helm to 3.16.4
• Start using intrinsic support for crds in Helm3. Change the existing directory structure and remove sub-directory charts/druid and instead just have top level charts. Add a new sub-directory charts/crds where the crds will be directly placed. Helm3 will automatically install the crds first.
• Remove config directory
• Move out config/samples to top level examples directory
• Remove charts/resources and provide a script to generate the tls-artifacts which can be used by consumers. These should not be checked into git repository but will become part of the OCI artifact once pushed.
• Remove the existing charts/druid/charts/crds and charts/druid/requirements.yaml
• create a script under hack/install-helm-scripts.sh to install helm charts which will copy crds, generate tls-artifacts. Now use helm utillities like Files.Glob to directly use these generate tls artifact files and encode them.
• Introduce a make target for building helm charts which will call hack/install-helm-scripts.sh
• Introduce a make target to push helm charts to the OCI registry.
• Add README.md under charts which will create detailed instructions on how to use the druid helm charts.
• Add templates/NOTES.txt which is a templatized file which will be rendered onto the console when you install a helm chart.
• Publish helm charts to a public OCI registry as an OCI artifact. Update the documentation and include steps on how to use helm OCI artifacts from the public OCI registry. Refer: https://helm.sh/docs/topics/registries/

Why is this needed:
We only wish to support deploying etcd-druid via helm charts. We have generated code under config directory to enable usage of kustomise but we not neither used it nor actively maintained it. It therefore makes sense to completely remove it and simplify the code base.