[cocl-operator] Integrate trustee and the cocl operator with secret database for storing the secret resource

[alicefr]

In confidential clusters, secrets such as encryption keys and passwords must be securely generated and stored. This issue proposes integrating the CL Operator, Trustee, and a secret management backend like Vault to support attestation-gated secret access.

Goal

• Enable the CL Operator to request and trigger secret (e.g., password) generation. The secret needs to be stored in a form which can be retrieved by Trustee.
• Store generated secrets securely in Vault.
• Allow Trustee to retrieve and deliver secrets only after successful attestation of the requesting workload.