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/gui/modules/submenu.h

@@ -1,10 +1,14 @@
 #pragma once
 #include <gui/view.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Submenu anonymous structure */
 typedef struct Submenu Submenu;
 typedef struct SubmenuItem SubmenuItem;
-typedef void (*SubmenuItemCallback)(void* context);
+typedef void (*SubmenuItemCallback)(void* context, uint32_t index);
 
 /* Allocate and initialize submenu
  * This submenu is used to select one option
@@ -25,6 +29,7 @@ View* submenu_get_view(Submenu* submenu);
 /* Add item to submenu
  * @param submenu - Submenu instance
  * @param label - menu item label
+ * @param index - menu item index, used for callback, may be the same with other items
  * @param callback - menu item callback
  * @param callback_context - menu item callback context
  * @return SubmenuItem instance that can be used to modify or delete that item
@@ -32,5 +37,15 @@ View* submenu_get_view(Submenu* submenu);
 SubmenuItem* submenu_add_item(
     Submenu* submenu,
     const char* label,
+    uint32_t index,
     SubmenuItemCallback callback,
-    void* callback_context);
+    void* callback_context);
+
+/* Remove all items from submenu
+ * @param submenu - Submenu instance
+ */
+void submenu_clean(Submenu* submenu);
+
+#ifdef __cplusplus
+}
+#endif