[FL-1884] GPIO application (#732)

* gpio: rename gpio application
* bq25896: add reading OTG config
* furi-hal-power: add is_otg_enabled API
* gpio: introduce new GPIO app, add OTG enable / disable
* variable-item-list: add enter callback
* gpio: add output test view and scene
* gpio app: fix GpioItemTester -> GpioItemTest

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

applications/gui/modules/variable-item-list.h

@@ -8,6 +8,7 @@ extern "C" {
 typedef struct VariableItemList VariableItemList;
 typedef struct VariableItem VariableItem;
 typedef void (*VariableItemChangeCallback)(VariableItem* item);
+typedef void (*VariableItemListEnterCallback)(void* context, uint32_t index);
 
 /** Allocate and initialize VariableItemList
  * @return VariableItemList* 
@@ -19,6 +20,9 @@ VariableItemList* variable_item_list_alloc();
  */
 void variable_item_list_free(VariableItemList* variable_item_list);
 
+/** Clear all elements from list
+ * @param variable_item_list VariableItemList instance
+ */
 void variable_item_list_clean(VariableItemList* variable_item_list);
 
 View* variable_item_list_get_view(VariableItemList* variable_item_list);
@@ -38,6 +42,16 @@ VariableItem* variable_item_list_add(
     VariableItemChangeCallback change_callback,
     void* context);
 
+/** Set enter callback
+ * @param variable_item_list VariableItemList instance
+ * @param calback VariableItemListEnterCallback instance
+ * @param context pointer to context
+ */
+void variable_item_list_set_enter_callback(
+    VariableItemList* variable_item_list,
+    VariableItemListEnterCallback callback,
+    void* context);
+
 /** Set item current selected index
  * @param item VariableItem* instance
  * @param current_value_index