GUI: status bar rendering. Power: battery indicator. (#207)

* Menu: animation. Irukagotchi: idle image.
* Power: battery, usb activity widget
* Power: tune battery max voltage and clamp overshoot
* get initial charge state

Co-authored-by: Aleksandr Kutuzov <aku@plooks.com>
Co-authored-by: aanper <mail@s3f.ru>

applications/gui/canvas_i.h

@@ -4,6 +4,8 @@ CanvasApi* canvas_api_init();
 
 void canvas_api_free(CanvasApi* api);
 
+void canvas_reset(CanvasApi* api);
+
 void canvas_commit(CanvasApi* api);
 
 void canvas_frame_set(