Move all sanitization operations from PK* and SAV* to PKX; add general
method for fetching a generation specific string
Changes the Text subform editor to show trash bytes when appropriate.
Special characters to be shown can be easily inserted in the future.
Initially populated with a filtered list, was unfiltered when
repopulated for legal moves. Just split legal/illegal, have the main
form choose which one is the stored list.
Remove unnecessary linq for other forms
Move System.Drawing usage out of Core to WinForms, as System.Drawing is
not in .NET Core/Standard. Simple methods to return resource name
strings have been added instead.
