* Fix Admin UI master list showing gRPC port instead of HTTP port for followers (#8867)
Raft stores server addresses as gRPC addresses. The Admin UI was using
these addresses directly via ToHttpAddress(), which cannot extract the
HTTP port from a plain gRPC address. Use GrpcAddressToServerAddress()
to properly convert gRPC addresses back to HTTP addresses.
* Use httpAddress consistently as masterMap key
Address review feedback: masterInfo.Address (HTTP form) was already
computed but the raw address was used as the map key, causing
potential key mismatches between topology and raft data.
Chris Lu