drpcserver: server interceptors tests

[shaikzakiriitm]

Stacked on #7
This draft pr serves as an example of how the server interceptors will look like in drpc.
Here, we cook up a dummy chat server, and wire logging interceptor with this server. The logging interceptor intercepts all message receives and sends on the server. Sample output from server's logs are shown below:

GOROOT=/Users/zakirhussainshaik/go/pkg/mod/golang.org/[email protected] #gosetup
GOPATH=/Users/zakirhussainshaik/go #gosetup
/Users/zakirhussainshaik/go/pkg/mod/golang.org/[email protected]/bin/go build -o /Users/zakirhussainshaik/Library/Caches/JetBrains/GoLand2025.1/tmp/GoLand/___go_build_storj_io_drpc_drpcserver_cmd /Users/zakirhussainshaik/go/src/github.com/drpc-fork-zakir/drpcserver/cmd/server_main.go #gosetup
/Users/zakirhussainshaik/Library/Caches/JetBrains/GoLand2025.1/tmp/GoLand/___go_build_storj_io_drpc_drpcserver_cmd #gosetup


2025/06/09 16:27:48 DRPC server listening on :9000
2025/06/09 16:28:11 Server Interceptor: RPC Method /drpcserver.chatpb.ChatService/ChatStream called
2025/06/09 16:28:11 Server Interceptor (/drpcserver.chatpb.ChatService/ChatStream): Received message: sender:"Client" text:"Hi"
2025/06/09 16:28:11 Received from Client: Hi
2025/06/09 16:28:11 Server Interceptor (/drpcserver.chatpb.ChatService/ChatStream): Sending message: sender:"Server" text:"Echo: Hi"
2025/06/09 16:28:11 Server Interceptor (/drpcserver.chatpb.ChatService/ChatStream): Received message: sender:"Client" text:"How are you?"
2025/06/09 16:28:11 Received from Client: How are you?
2025/06/09 16:28:11 Server Interceptor (/drpcserver.chatpb.ChatService/ChatStream): Sending message: sender:"Server" text:"Echo: How are you?"
2025/06/09 16:28:11 Server Interceptor (/drpcserver.chatpb.ChatService/ChatStream): Received message: sender:"Client" text:"Bye!"
2025/06/09 16:28:11 Received from Client: Bye!
2025/06/09 16:28:11 Server Interceptor (/drpcserver.chatpb.ChatService/ChatStream): Sending message: sender:"Server" text:"Echo: Bye!"
2025/06/09 16:28:11 stream closed or errored: context canceled
2025/06/09 16:28:11 Server Interceptor: RPC Method /drpcserver.chatpb.ChatService/ChatStream completed with error: context canceled (Duration: 921.458µs)

Process finished with the exit code 130 (interrupted by signal 2:SIGINT)