Gui: refactor buttons remapping (#1949)

* Gui: refactor buttons remapping
  Instead of calling 3 separate functions with a ton of switch/case statements,
  use a 2-dimensional lookup table to remap buttons based on the orientation.
* Gui: cleanup input mapping and fix incorrect asserts
* SnakeGame: handle input special case

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

firmware/targets/f7/furi_hal/furi_hal_resources.h

@@ -20,6 +20,7 @@ typedef enum {
     InputKeyLeft,
     InputKeyOk,
     InputKeyBack,
+    InputKeyMAX, /**< Special value */
 } InputKey;
 
 /* Light */