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/OpenGLSupport.cpp

@@ -72,9 +72,9 @@ bool BuildShaderProgram(const char* vs, const char* fs, GLuint* ids, const char*
         //printf("shader source:\n--\n%s\n--\n", fs);
         delete[] log;
 
-        FILE* logf = fopen("shaderfail.log", "w");
-        fwrite(fs, len+1, 1, logf);
-        fclose(logf);
+        Platform::FileHandle* logf = Platform::OpenFile("shaderfail.log", Platform::FileMode::WriteText);
+        Platform::FileWrite(fs, len+1, 1, logf);
+        Platform::CloseFile(logf);
 
         glDeleteShader(ids[0]);
         glDeleteShader(ids[1]);