expose jsonrpc-core client (#672)

* expose jsonrpc-core client

* use shared reference to RpcClienT

* don't expose Arc<dyn RpcClientT>

* cargo fmt

subxt/src/rpc/rpc.rs

@@ -76,7 +76,10 @@ use sp_runtime::{
     },
     ApplyExtrinsicResult,
 };
-use std::collections::HashMap;
+use std::{
+    collections::HashMap,
+    sync::Arc,
+};
 
 /// A number type that can be serialized both as a number or a string that encodes a number in a
 /// string.
@@ -342,7 +345,7 @@ impl<T: Config> std::ops::Deref for Rpc<T> {
 
 impl<T: Config> Rpc<T> {
     /// Create a new [`Rpc`]
-    pub fn new<R: RpcClientT>(client: R) -> Self {
+    pub fn new<R: RpcClientT>(client: Arc<R>) -> Self {
         Self {
             client: RpcClient::new(client),
             _marker: PhantomDataSendSync::new(),

subxt/src/rpc/rpc_client.rs

@@ -31,8 +31,8 @@ use std::{
 pub struct RpcClient(Arc<dyn RpcClientT>);
 
 impl RpcClient {
-    pub(crate) fn new<R: RpcClientT>(client: R) -> Self {
-        RpcClient(Arc::new(client))
+    pub(crate) fn new<R: RpcClientT>(client: Arc<R>) -> Self {
+        RpcClient(client)
     }
 
     /// Make an RPC request, given a method name and some parameters.