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/storage/gptmenu.c

@@ -82,6 +82,7 @@ void GptMenu(u8 MMCType){
             else {
                 if (TConf.curExplorerLoc > LOC_SD)
                     ResetCopyParams();
+                    
                 TConf.curExplorerLoc = LOC_EMMC;
                 FileExplorer("bis:/");
             }