Runtime/jit repoints these to the dll rather than heap if we're Little Endian (always, otherwise will allocate like before).
Eliminates quite a few static constructors, so even faster startup. Items later.
In this pull request I've changed a ton of method signatures to reflect the more-narrow types of Species, Move# and Form; additionally, I've narrowed other large collections that stored lists of species / permitted values, and reworked them to be more performant with the latest API spaghetti that PKHeX provides. Roamer met locations, usually in a range of [max-min]<64, can be quickly checked using a bitflag operation on a UInt64. Other collections (like "Is this from Colosseum or XD") were eliminated -- shadow state is not transferred COLO<->XD, so having a Shadow ID or matching the met location from a gift/wild encounter is a sufficient check for "originated in XD".
Existing `get`/`set` logic is flawed in that it doesn't work on Big Endian operating systems, and it allocates heap objects when it doesn't need to.
`System.Buffers.Binary.BinaryPrimitives` in the `System.Memory` NuGet package provides both Little Endian and Big Endian methods to read and write data; all the `get`/`set` operations have been reworked to use this new API. This removes the need for PKHeX's manual `BigEndian` class, as all functions are already covered by the BinaryPrimitives API.
The `StringConverter` has now been rewritten to accept a Span to read from & write to, no longer requiring a temporary StringBuilder.
Other Fixes included:
- The Super Training UI for Gen6 has been reworked according to the latest block structure additions.
- Cloning a Stadium2 Save File now works correctly (opening from the Folder browser list).
- Checksum & Sanity properties removed from parent PKM class, and is now implemented via interface.
