Update code for rpc-server

[belog2867]

The current rpc-server code is somewhat outdated and lacks support for certain backends, such as OpenCL. I believe the code should be updated and maintained to support multiple GPUs and various backends within a single rpc-server process. Additionally, the network transmission for RPC should be optimized to improve efficiency, while giving users the flexibility to choose between a network-based transmission model or a local one.