C++ apps: templated scene controller (#517)

* C++ apps: templated scene controller
* templated app: fix type names
* templated app: text store component
* Applications: add "Templated Scene" application
* templated app: refractoring
* Gui module byte input: fix docs
* templated app: new byte input scene
* templated app: dialog ex view module
* templated app: popup view module
* templated app: dialog-ex view module, fix docs
* templated app: text input view module
* Gui module text input: fix docs
* Furi: duplicated include
* templated app: record holder (controller) class
* templated app: view modules can now be accessed via cast
* templated app: remove unused includes
* templated app: fix return code

applications/scened-app-example/scene/scened-app-scene-start.h

@@ -0,0 +1,13 @@
+#pragma once
+#include "../scened-app.h"
+
+class ScenedAppSceneStart : public GenericScene<ScenedApp> {
+public:
+    void on_enter(ScenedApp* app, bool need_restore) final;
+    bool on_event(ScenedApp* app, ScenedApp::Event* event) final;
+    void on_exit(ScenedApp* app) final;
+
+private:
+    void submenu_callback(void* context, uint32_t index);
+    uint32_t submenu_item_selected = 0;
+};