fix: Updates serialization to use v2.0 (#998)

- [X] Deletes serialization annotations
- [X] Updates to ModernUO.Serialization.Annotations nuget
- [X] Updates serializer to v2.0
- [X] Changes all `Serializable()` to `SerializationGenerator()`
- [X] Updates to schema generator v2.0

Projects/UOContent/Items/Special/SoulStone.cs

@@ -1,5 +1,4 @@
 using System;
-using Server.Accounting;
 using Server.Engines.VeteranRewards;
 using Server.Factions;
 using Server.Gumps;