Completely new text viewer app (proper newlines)

Code borrowed from archive app show scene, will be used to replace that

applications/external/text_viewer/scenes/text_viewer_scene.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <gui/scene_manager.h>
+
+// Generate scene id and total number
+#define ADD_SCENE(prefix, name, id) TextViewerScene##id,
+typedef enum {
+#include "text_viewer_scene_config.h"
+    TextViewerSceneNum,
+} TextViewerScene;
+#undef ADD_SCENE
+
+extern const SceneManagerHandlers text_viewer_scene_handlers;
+
+// Generate scene on_enter handlers declaration
+#define ADD_SCENE(prefix, name, id) void prefix##_scene_##name##_on_enter(void*);
+#include "text_viewer_scene_config.h"
+#undef ADD_SCENE
+
+// Generate scene on_event handlers declaration
+#define ADD_SCENE(prefix, name, id) \
+    bool prefix##_scene_##name##_on_event(void* context, SceneManagerEvent event);
+#include "text_viewer_scene_config.h"
+#undef ADD_SCENE
+
+// Generate scene on_exit handlers declaration
+#define ADD_SCENE(prefix, name, id) void prefix##_scene_##name##_on_exit(void* context);
+#include "text_viewer_scene_config.h"
+#undef ADD_SCENE