Add PSV support

[root670]

Add a class named PSVFile implementing ISaveFile for PSV files. Add support for using the class in SaveFileFactory::createSaveFile().

This format is used by the PS2 emulator on PS3.

[bucanero]

hello @root670

I was looking for some PS2 save format details (.psu, .max, .cbs), and I found your Cheat Device implementation. I ended up using it in my PS3 homebrew, Apollo Save Tool, to convert them to PSV. 👍

in case you still want to add PSV support, you can check the source code from my PSV converter tool:
https://github.com/bucanero/psv-save-converter
the code includes the conversion from psu/max format to .psv, and also resigns the .psv file properly so it can be imported by a PS3.

it's in C, but it should be simple enough to use the code as a base for your C++ .psv class.

btw, you can also find the code in my Apollo Tool, but since the PS3 is big-endian there's a lot of endianness swapping around. The code from the basic psv-save-converter should be easier to use, as it assumes little-endian arch.

I hope it helps! 😄 cheers