[Feature] Entity Tags (eTags) for Concurrency Control

[ReginaLin24]

When a request to the cluster is made, the system checks whether the provided eTag header matches the latest version stored in the database. If there is a mismatch, the request fails early, ensuring that no unintended overwrites occur.

More can be found in https://learn.microsoft.com/en-us/azure/aks/use-etags