add docs, move some data fetching to more appropriate class
remove old XP memecrypto support handling, was previously removed due to
net standard/core split
refactor memecrypto to handle multiple save sizes (USUM won't be the
same size save file); placeholder -1 for USUM size
I recently learned about targetting multiple frameworks in .Net Standard libraries. The main benefit here si taht PKHeX.WinForms and PKHeX.Tests no longer need to carry around the .Net Core DLLs. While it's now an option, I encourage PKHeX.Core to avoid framework-specific compiler directives.
Prefer 32-bit is enabled, so there will be no functional difference from before, except that any of the assemblies can be referenced by a 64-bit process.
