Older games aren't fond of how our sceVideodec2GetPictureInfo implementation outputs AVC picture info after the struct size increase.
Adding the old struct, and additional code using it for these games works around this problem.
Neither sceVideodec2Decode or sceVideodec2Flush should be modifying the output's `thisSize`, doing so breaks older games now that we have the updated structs.
We should also only set frameFormat and framePitchInBytes if the game inputted the newer struct, since otherwise we're modifying memory the game never gave us.
These changes might fix the regression in Hatsune Miku Project Diva X, though it's hard to tell due to some weird caching issue with Windows, and the ancient regression this game had on Linux.
* Update file_system.cpp
* libSceVideodec2 struct fixes
Our code was based on an old version of the libSceVideodec2 library. Based on what I've decompiled, these structs changed somewhere around firmware 6.50, and newer versions of the library have these flexible checks to accommodate both variants of the structs.
* Static assert for AvcPictureInfo struct
All the other Videodec2 structs have static asserts, might as well use one here too.
* Initialize new values
Set proper values for frameFormat and framePitchInBytes.
`frame->linesize[0]` appears to be in bytes already, I'm not sure if that means framePitch is being set wrong though.
* core: Split error codes into separate files
* Reduces build times and is cleaner
* core: Bring structs and enums to codebase style
* core: More style changes
