Removing usage of legacy per property metadata keys in AutoFGD in favor of KV3 metadata section like entities already use The old and new systems cannot be used together (like Asset AutoFGD was trying to do), and the new system allows for any random key-value sets to be stored, not only those from a predefined set in the old system. This commit also loads data from the new system into the internal fields old system was loading into, so there's no functionality loss. Obsoletes Hammer.FieldMetaDataAttribute.AddMetadata( List<string> ) in favor of AddMetadata( Dictionary<string, string> )