Remove tuples from JSON RPC responses (#7806)

* Remove RpcConfirmedBlock tuple

* Remove getRecentBlockhash tuple

* Remove getProgramAccounts tuple

* Remove tuple from get_signature_confirmation_status

* Collect Rpc response types

* Camel-case epoch schedule for rpc response

* Remove getBlockCommitment tuple

* Remove getStorageTurn tuple

* Update json-rpc docs

client/src/lib.rs

@@ -8,4 +8,5 @@ pub mod perf_utils;
 pub mod rpc_client;
 pub mod rpc_client_request;
 pub mod rpc_request;
+pub mod rpc_response;
 pub mod thin_client;