feat: include called service URI in StatusRuntimeException description

[He-Pin]

Motivation

When a gRPC call fails, the StatusRuntimeException description only contained the raw gRPC status message. In systems with multiple services, it was difficult to tell which service caused the failure, particularly for generic error codes like UNAVAILABLE or CANCELLED.

Modification

• Added requestUri: Uri as a first parameter to the internal PekkoHttpClientUtils.responseToSource, mapToStatusException, and parseResponseStatus methods
• Appended "When calling rpc service: <URI>" to the exception description via Status.augmentDescription() in both branches of mapToStatusException (the "no grpc-status" and "non-zero status code" paths)
• Updated PekkoHttpClientUtilsSpec tests to pass requestUri to all responseToSource calls
• Updated PekkoGrpcScalaClientTester interop test assertion to use startsWith (since the description now has an appended URI suffix)
• Added MiMa backwards-compatibility filter for the changed internal responseToSource signature

Result

Error messages now include the called service URI, making debugging significantly easier:

UNAVAILABLE: connection refused. When calling rpc service: https://myservice.example.com/my.Service/Method

Note: PR #646 by @pjfanning independently migrates the same upstream change. This PR is provided for migration traceability purposes.

References

• Upstream commit (which is now Apache licensed): akka/akka-grpc@82e0413e
• Upstream PR: feat: Include information about called service in StatusRuntimeException akka/akka-grpc#1748
• Related PR in this repo: Add request URI to gRPC client error descriptions #646

[pjfanning]

@He-Pin this is a duplicate of #646

@raboof has highlighted some security concerns in that PR.

I can fix up #646 if it is agreed how to proceed but at the moment, I agree with @raboof that we shouldn't make exactly the Akka change.