Automatic merge from submit-queue (batch tested with PRs 46429, 46308, 46395, 45867, 45492)
deduplicate endpoints before DNS registration
**What this PR does / why we need it**: Multizone clusters will return duplicated endpoints to the federation controller manager. The FCM will then attempt to create an A record with duplicate entries, which will fail. As a result, federated services on multi-AZ clusters don't work right now. This PR deduplicates the endpoint IPs before attempting the DNS record registration.
**Which issue this PR fixes**: fixes#35997
**Special notes for your reviewer**:
I believe there is a lot of refactoring required with multizone federated clusters, most notably with regard to AWS and optimising for ALIAS records rather than A, but this PR will at least allow basic functionality to work.
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