Subghz app example (#365)

* Gui: ported submenu and view_dispatcher_remove_view from iButton branch

* App gui-test: use backported submenu api

* App subghz: initial commit

* App subghz: syntax fix

* App gui-test: fix submenu callback

* App subghz: add subfolders to build

* Gui view: c++ verison of with_view_model

* Subghz app: simple spectrum settings view

* Subghz app: add spectrum settings view to view manager

* Subghz app: spectrum settings scene

Co-authored-by: coreglitch <mail@s3f.ru>

applications/subghz/subghz-app.h

@@ -0,0 +1,37 @@
+#pragma once
+#include <map>
+#include <list>
+#include "subghz-view-manager.h"
+
+#include "scene/subghz-scene-start.h"
+#include "scene/subghz-scene-spectrum-settings.h"
+
+class SubghzApp {
+public:
+    void run(void);
+
+    SubghzApp();
+    ~SubghzApp();
+
+    enum class Scene : uint8_t {
+        SceneExit,
+        SceneStart,
+        SceneSpectrumSettings,
+    };
+
+    SubghzAppViewManager* get_view_manager();
+    void switch_to_next_scene(Scene index);
+    void search_and_switch_to_previous_scene(std::initializer_list<Scene> scenes_list);
+    bool switch_to_previous_scene(uint8_t count = 1);
+    Scene get_previous_scene();
+
+private:
+    std::list<Scene> previous_scenes_list = {Scene::SceneExit};
+    Scene current_scene = Scene::SceneStart;
+    SubghzAppViewManager view;
+
+    std::map<Scene, SubghzScene*> scenes = {
+        {Scene::SceneStart, new SubghzSceneStart()},
+        {Scene::SceneSpectrumSettings, new SubghzSceneSpectrumSettings()},
+    };
+};