Modest cleanups for DSi_NAND (#1714)

* Add a definition for TMD files

* Wrap TitleMetadata in a namespace

* Add a comment

* Remove TitleMetadataCertificate

- melonDS ignores it anyway

* Refactor the use of title metadata

- Move bitwise operations on the title ID into helper methods
- Use TitleMetadata objects instead of pointers to raw data

* Slight cleanup in DSi_NAND

- Replace some constants with sizeof
- Use an NDSHeader object instead of a raw array of bytes

* Add a DSi_NAND::ImportFile overload that loads a file from memory

* Split most of ImportTitle into InitTitleFileStructure

- It will be reused in the next commit

* Add ability to import title from memory

* Fix another potential issue

* Fix broken DSiWare installation

- The bytes of the title ID/category were being swapped in most places, but not all

* Add some logging calls

* Declare array sizes in DSi_TMD in decimal, not hex

* Add a space after the #endif

- To adhere to the style guide

* Assert the size of TitleMetadataContent

* Change the type of SignatureName

* Don't mark the TMD structs as packed

* Remove extraneous comments

* Cut down some newlines

src/DSi_NAND.h

@@ -21,6 +21,7 @@
 
 #include "types.h"
 #include "NDS_Header.h"
+#include "DSi_TMD.h"
 #include <vector>
 #include <string>
 
@@ -49,7 +50,8 @@ void PatchUserData();
 void ListTitles(u32 category, std::vector<u32>& titlelist);
 bool TitleExists(u32 category, u32 titleid);
 void GetTitleInfo(u32 category, u32 titleid, u32& version, NDSHeader* header, NDSBanner* banner);
-bool ImportTitle(const char* appfile, u8* tmd, bool readonly);
+bool ImportTitle(const char* appfile, const DSi_TMD::TitleMetadata& tmd, bool readonly);
+bool ImportTitle(const u8* app, size_t appLength, const DSi_TMD::TitleMetadata& tmd, bool readonly);
 void DeleteTitle(u32 category, u32 titleid);
 
 u32 GetTitleDataMask(u32 category, u32 titleid);