Support client side reflection

[Zane-XY]

Feature Request

Crates

Motivation

The motivation comes from a use case in LLM function calling, which returns the function name and it's arguments in a json format:

 "tool_calls": [
          {
            "function": {
              "arguments": "{\"namespace_path\":\"***.Resource\"}",
              "name": "search_file"
            },
            "id": "call_KS7yzQlKaa4qBMPNwKPBS8uX",
            "index": 0,
            "type": "function"
          }
        ]

The function search_file is actually a gPRC method hosted in the remote server. I'm looking for ways to make generic gRPC calls without deconstructing the arguments into the required proto message struct. Actually, I don't and shouldn't care about the structure of the request and response.

Proposal

Should support such client side reflection or ways to make generic rpc calls.

Alternatives

a related crate might be https://crates.io/crates/prost-reflect. I hope this can be supported by tonic natively.