chore: Combine the EFS CSI example with the stateful example

[bryantbiggs]

What does this PR do?

• Combine the EFS CSI example with the stateful example

Motivation

• We have a stateful example that shows how to backup clusters using velero, and a aws-efs-csi example which shows adding just the EFS CSI driver and EFS resources. It doesn't make sense to have these separate; instead they should be combined to show how to run stateful workloads including managing backups, etc.

More

• Yes, I have tested the PR using my local account setup (Provide any test evidence report under Additional Notes)
• Yes, I have added a new example under examples to support my PR
• Yes, I have created another PR for add-ons under add-ons repo (if applicable)
• Yes, I have updated the docs for this feature
• Yes, I ran pre-commit run -a with this PR

Note: Not all the PRs required examples and docs except a new pattern or add-on added.

For Moderators

• E2E Test successfully complete before merge?

Additional Notes

[bryantbiggs]

I think that check will fail because I removed the directory but it exists on main? maybe?

[vara-bonthu]

Good decision 👍🏼