Goal: 

Extend gophercloud's Designate DNS v2 API client to support TSIG (Transaction Signature) key operations. TSIG keys are used for authenticating DNS zone transfers and NOTIFY messages between DNS servers. This functionality is currently missing from gophercloud and requires custom implementation.

Acceptance Criteria:

  - Verify package follows gophercloud v2 conventions and patterns
  - Verify necessary CRUD operations are implemented
  - Verify acceptance tests validate operations against live Designate API
  - Verify documentation includes examples for common use cases
  - Verify code passes gophercloud CI/CD checks

Note: while this ticket is important, it is not mandatory to implement it for a Minimum Viable Product /MVP/Feature, as we can use Gophercloud's low-level HTTP request methods to call tsigkeys operations. But we should implement it so multipool will be more maintainable.