[ENH] - Expose Backup and Restore for Keycloak API

[viniciusdc]

Create a stage for the backup-restore application to run as a default service within nebari. This will be possible since the service has its own helm chart which could be used by the new KustomizeStage class for quick deployment. Or, as a POC using the helm-extensions.

[viniciusdc]

We fixed a bug with the storage class. Now, you only need to ship the source package in a way Nebari can easily consume. The current strategy includes a helm chart for Kubernetes deployment and deployment within Nebari.

This might not be enough, as we still would require a terraform resource to create the necessary keycloak client with the proper rights over Nebari's realm.

[viniciusdc]

Following tasks to be incldued in the helm chart:

• expected values
• configmaps for keycloak credentials and storage

[viniciusdc]

public code repo https://github.com/nebari-dev/backup-restore

[viniciusdc]

This will be shipped using dockerfile only as a container, and the pod spec will be present as a service within nebari, once its out of experimental, we can rethink the helm chart, as this requires maintainability of a helm index (simple to make, but extra work for now)