How to categorize this issue?
/kind enhancement
/area quality

What would you like to be added:
Validation for the fields within the etcd resource to be done within etcd-druid. This would be done using x-validations wherein the validation rules are written using CEL expressions.

Why is this needed:
This would ensure that the validations for etcd are done within etcd-druid. By using CEL expressions, we can validate resource fields without requiring an external validating webhook. Since these CEL expressions are compiled and type checked against a CRD's schema when the CRDs are created and updated, Cluster operability improves because CRD validation no longer requires a remote call to a webhook endpoint, eliminating a potential point of failure.

Supersedes #409 . Please check #409 for history of arriving at CEL expressions as a viable solution for validation.
TODO

• Add CRD validations
• Add integration tests for each field being validated
• Add documentation for the list of validations being done