A minimal gRPC unary client over HTTP/2 (via Mint), speaking the cleartext
(h2c) protocol Hedera consensus nodes serve on port 50211. Handles the 5-byte
gRPC length-prefixed framing and the grpc-status trailer; enough for the
single-request/single-response calls this SDK makes.
Summary
Functions
Make a unary gRPC call: send message (raw protobuf bytes) to path on
host:port, return {:ok, response_bytes} or {:error, reason}.