Add missing VinylDNS API endpoints

[Sokitha-21]

• Added endpoint builders and query helpers for health/status, zones, record sets, groups and users.
• Implemented client methods for monitoring, status management, backend IDs, deleted zones, ACL rule add/delete, record set metrics and history, group utilities, and user administration.
• Introduced ownership transfer helpers for record sets (request/approve/reject/cancel) that wrap record set update payloads.
• Added unit tests covering all new endpoints and client methods.
• Fix SigV4 signing for DELETE endpoint.

[snyk-io]

✅ Snyk checks have passed. No issues have been found so far.

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✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues

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[JoshSEdwards]

Just a few minor Javadoc discrepancies and some suggestions to make error handling more consistent.