Each archive now takes a mount point of either NAND or SDMC, and builds its own directory structure there, trying to simulate an HLE-friendly hardware layout

under /nand/title/high/low/content/00000000.app.romfs

This is to better represent the hardware layout, they are still aren't quite accurate, but this better and will help a bit when implementing the other archives like NAND-RO and NAND-RW

Fixed a few warnings and cleaned up the code

This allows Steel Diver to boot further, some files are needed.

This is still not ready and needs a big cleanup, this will possibly be delayed until the way we handle archives is fixed (with factory classes instead of ahead-of-time creation of archives)

They will be stored in /extsavedata/SDMC and /extsavedata/NAND respectively.
Also redirect some APT_A functions to their APT_U equivalents.
Implemented the gamecoin.dat file in SharedExtSaveData in the PTM module.
Implemented formatting the savegame.
Retake a previous savegame if it exists instead of reporting them as not formatted every time a game is loaded.

Moved most of the shared CFG code there, implemented a few CFG:I functions

It is now kept in memory as per 3dbrew, all updates happen on memory, then they can be saved using UpdateConfigNANDSavegame.

Added a "config" file to the CFG process service (CFG:U), and added a few default blocks to it.

Implemented GetSystemModel and GetModelNintendo2DS

Tested with hwtests.

Maybe sometime when we actually implement that

It will be stored in the /syssavedata folder. This archive is user by various Services and possibly games via the FS:U service.

The savedata for each game is stored in /savedata/<ProgramID> for NCCH files. ELF files and 3DSX files use the folder 0 because they have no ID information

Got rid of the code duplication in File and Directory

Files that deal with the host machine's file system now live in DiskFile, similarly for directories and DiskDirectory and archives with DiskArchive.

FS_U: Use the correct error code when a file wasn't found

- Refactor FS::Archive internals to make Archive creation and lifetime
  management clearer.
- Remove the "Archive as a File" hack.
- Implement 64-bit Archive handles.

The 3DS allows the user to read from files opened with the Write access modifier, even if he did not specify the Read access modifier.

Open the files in binary mode so that we can prevent CR/LF problems in Windows, where a line-end is replaced by these two bytes instead of just 0xA, this was causing problems with the GetSize test

This is in line with what the hardware itself does.

It does this by splitting the initial directory opening into Directory.Open(), which will return false if a stat fails.
Then, Archive::OpenDirectory will return nullptr, and archive.cpp will return an error code .