[FL-1792] RPC service (#698)

* Lib: added nanopb
* Hal rfid: fixed confused arguments
* Lib: update makefile, include nanopb
* Lib: remove nanopb
* Lib: add nanopb as submodule
* Assets: remove protobuf
* Assets: add protobuf message definitions as submodule
* WIP: [FL-1792] Add Protobuf RPC
* WIP: RPC add ping
* Add Ping
* Fix Ping, Add (WIP) storage
* Update submodule
* ble-glue: add ptotobuf to ble
* WIP: Add storage list test
* revert applications.mk
* Add Storage List command
* ble-glue: fix fast updating rx charachteristic
* ble serial: split long ble packets
* Add Storage Read/Write/Mkdir/Delete
* Disable tests
* Rename Element -> File
* Add md5sum, fix test leak
* Regenerate Protobuf
* Fix review comments
* ble-glue: sync f7 target

Co-authored-by: Albert Kharisov <albert@flipperdevices.com>
Co-authored-by: gornekich <n.gorbadey@gmail.com>
Co-authored-by: あく <alleteam@gmail.com>

applications/rpc/rpc.h

@@ -0,0 +1,16 @@
+#pragma once
+#include <stddef.h>
+#include <stdint.h>
+#include "cmsis_os.h"
+
+typedef struct Rpc Rpc;
+typedef struct RpcSession RpcSession;
+
+typedef void (*RpcSendBytesCallback)(void* context, uint8_t* bytes, size_t bytes_len);
+
+RpcSession* rpc_open_session(Rpc* rpc);
+void rpc_close_session(RpcSession* session);
+/* WARN: can't call RPC API within RpcSendBytesCallback */
+void rpc_set_send_bytes_callback(RpcSession* session, RpcSendBytesCallback callback, void* context);
+size_t
+    rpc_feed_bytes(RpcSession* session, uint8_t* encoded_bytes, size_t size, TickType_t timeout);