Add fw dumping

- also fatfs is stupid
- also close files properly on a failed copy
- also check for errors during folder readouts
- also make sure holding vol- doesn't dump the keys anyway

source/gfx/gfxutils.h

@@ -14,4 +14,5 @@
 #define RGBUnionToU32(optionUnion) (optionUnion | 0xFF000000)
 
 void gfx_clearscreen();
-int MakeHorizontalMenu(MenuEntry_t *entries, int len, int spacesBetween, u32 bg);
+int MakeHorizontalMenu(MenuEntry_t *entries, int len, int spacesBetween, u32 bg);
+int MakeYesNoHorzMenu(int spacesBetween, u32 bg);