Similar to the migration of splitting DatFile into ifferent subtypes, this makes sure that logic that petains to each "type" of file that's used by SabreTools, be it an input/output archive format or a specialty file format that is treated by itself like CHDs, is in tis own namespace. ArchiveTools has been pared down accordingly and all "factory" logic should make it easier to add more formats in the future with little fuss.
In this new update mode, a set of base DATs can be used as a replacement naming scheme for the input DATs. Only the item names will be updated, so this willl not fill in additional hashes or the like.
This DOES group some kinds of DAT due to their inherently similar nature. TSV and CSV are under the same "SeparatedValue" umbrella, and all of the SFV, MD5, SHA1, etc are under Hashfile because they're nearly identical. This is just the first stage change, making everything static and making them reference the DatFile separately.
BiosSet is the only DatItem type that, by default, has a "Description" field and it was overriding the Machine variant. To make things more consistent, I have renamed this one field since, technically speaking, it is a Machine description, not the DatItem one.
