[FL-2589] RPC App control commands (#1350)

* RPC App control commands
* Button release timeout
* SubGhz tx fix

Co-authored-by: Aleksandr Kutuzov <alleteam@gmail.com>

applications/nfc/scenes/nfc_scene_rpc.c

@@ -0,0 +1,34 @@
+#include "../nfc_i.h"
+
+void nfc_scene_rpc_on_enter(void* context) {
+    Nfc* nfc = context;
+    Widget* widget = nfc->widget;
+
+    widget_add_text_box_element(
+        widget, 0, 0, 128, 28, AlignCenter, AlignCenter, "RPC mode", false);
+
+    notification_message(nfc->notifications, &sequence_display_backlight_on);
+
+    view_dispatcher_switch_to_view(nfc->view_dispatcher, NfcViewWidget);
+}
+
+bool nfc_scene_rpc_on_event(void* context, SceneManagerEvent event) {
+    Nfc* nfc = context;
+    bool consumed = false;
+
+    if(event.type == SceneManagerEventTypeCustom) {
+        consumed = true;
+        if(event.event == NfcCustomEventViewExit) {
+            view_dispatcher_stop(nfc->view_dispatcher);
+        }
+    }
+    return consumed;
+}
+
+void nfc_scene_rpc_on_exit(void* context) {
+    Nfc* nfc = context;
+
+    nfc_rpc_exit_callback(nfc);
+
+    widget_reset(nfc->widget);
+}