Disassociate pk4/pk6 backing byte[] when converting to pk5|pk7, as we no longer make a copy of the byte[] in the pkm's constructor.
Change UpdatePKM to include isParty, as we want it optional to update FormArgument too.
Change FormArgument saving to be handled by FormConverter; kinda not really good to have it there, but nothing else is handling FormArgument values.
Expand IFormArgument to have all FormArgument values exposed. "Maximum" is furfrou only.
PK6: Max is in the "FormArgument" u32, and the remain/elapsed is in party stats (hence the reverting when boxed)
PK7: u8 remain, u8 elapsed, u8 max, u8 unused.
PK8: assumedly the same as PK7, given the disassembly hints that it's the same as past games (even though Furfrou and Hoopa are not in SWSH).
AltForm & Form & Forme => Form
GenNumber & Generation => Generation
Extract out SpeciesForm interface, and re-add IGeneration
For those using PKHeX as a dependency, this should be a pretty straightforward manual replacement... GenNumber and AltForm should be quick find-replace`s.