* rpc module: refactor calls/subs without a server

* Update utils/src/server/rpc_module.rs

* Update utils/src/server/rpc_module.rs

* Update utils/src/server/rpc_module.rs

* rpc module: add raw_json_requests + rename test_subscribe

* Update utils/src/server/rpc_module.rs

Co-authored-by: David <[email protected]>

* add rustdoc examples

* fix tabs

* no more tabs in docs

* address grumbles

* Update utils/src/server/rpc_module.rs

Co-authored-by: David <[email protected]>