Rpc to return software version (#5456)

* Add getSoftwareVersion rpc

* Add getSoftwareVersion to doc

* Rename to getVersion and return object

* Update jsonrpc-api.md

core/src/lib.rs

@@ -73,6 +73,7 @@ pub mod test_tx;
 pub mod tpu;
 pub mod tvu;
 pub mod validator;
+pub(crate) mod version;
 pub mod weighted_shuffle;
 pub mod window_service;