Make a global cached rpc client

[Ted-Jiang]

Hi expert !
Our client is basic tonic::client::Grpc<tonic::transport::Channel> , try put it in the rust GLOBAL_VALUE like pub static for reuse in in global.

Found the doc said
https://github.com/hyperium/tonic/blob/b3fca19104bf001d3a3dac74221b7c9bede13cf1/tonic/src/transport/channel/mod.rs#L52C3-L56

/// Sending a request on a channel requires a `&mut self` and thus can only send
/// one request in flight. This is intentional and is required to follow the `Service`
/// contract from the `tower` library which this channel implementation is built on
/// top of.

Is it ok to use the single global client do RPC call get Steam results in parallel 🤔 ? How should i check this from the code? if you have any suggestion really appreciate