Miscellaneous DSi NAND fixes (#1852)

* Replace some standard I/O calls with Platform equivalents

- I missed a spot when I submitted that PR a few months ago

* Include <memory> in DSi_NAND.h

- Because it uses unique_ptr

* Split DSi_NAND::ReadHardwareInfo into ReadSerialData and ReadHardwareInfoN

* Add a RegionMask enum

* Move DSi NAND patching to the frontend

* Add DSiSupportedLanguageMask

- Not currently used by the frontend, but I use it in melonDS DS

* Remove some Platform::ConfigEntry values

- The core no longer needs to know about them
- The corresponding Config values are unchanged

* Mark NANDMount's destructor as noexcept

src/NDS_Header.h

@@ -22,6 +22,21 @@
 #include <string.h>
 #include "types.h"
 
+/// Set to indicate the console regions that a ROM (including DSiWare)
+/// can be played on.
+enum RegionMask : u32
+{
+    NoRegion = 0,
+    Japan = 1 << 0,
+    USA = 1 << 1,
+    Europe = 1 << 2,
+    Australia = 1 << 3,
+    China = 1 << 4,
+    Korea = 1 << 5,
+    Reserved = ~(Japan | USA | Europe | Australia | China | Korea),
+    RegionFree = 0xFFFFFFFF,
+};
+
 // Consult GBATEK for info on what these are
 struct NDSHeader
 {
@@ -105,7 +120,7 @@ struct NDSHeader
     u8 DSiMBKWriteProtect[3]; // global MBK9 setting
     u8 DSiWRAMCntSetting; // global WRAMCNT setting
 
-    u32 DSiRegionMask;
+    RegionMask DSiRegionMask;
     u32 DSiPermissions[2];
     u8 Reserved6[3];
     u8 AppFlags; // flags at 1BF