remote ext: make it possible to use an existing ws connection (#10737)

* remote ext: make it possible to pass ws client

* grumbles: introduce `map_uri`

substrate/utils/frame/remote-externalities/src/rpc_api.rs

@@ -19,8 +19,8 @@
 // TODO: Consolidate one off RPC calls https://github.com/paritytech/substrate/issues/8988
 
 use jsonrpsee::{
+	core::client::ClientT,
 	rpc_params,
-	types::traits::Client,
 	ws_client::{WsClient, WsClientBuilder},
 };
 use sp_runtime::{
@@ -73,7 +73,7 @@ where
 	Ok(signed_block.block)
 }
 
-/// Build a website client that connects to `from`.
+/// Build a websocket client that connects to `from`.
 async fn build_client<S: AsRef<str>>(from: S) -> Result<WsClient, String> {
 	WsClientBuilder::default()
 		.max_request_body_size(u32::MAX)