Is your feature request related to a problem? Please describe.
Support for OVHcloud KMS (OKMS) service keys as an auto-unseal backend for OpenBao is currently being implemented in response to openbao/openbao#1054.
However, go-kms-wrapping does not provide a wrapper for OKMS, which is required for this implementation.

Describe the solution you'd like
Add a new OKMS wrapper responsible for:

• Handling OKMS configuration
• Performing encryption and decryption operations using the OKMS Service Keys API (or any compatible API).

This wrapper follows the same design as existing KMS wrappers.
The implementation is complete and ready for review.