Support chia 1.4.0

NFT support with Chia 1.4.0

https://www.nuget.org/packages/chia-dotnet/1.4.0

What's Changed

• add missing header hash by @wizicer in #52
• 1.4.0 by @dkackman in #53

Full Changelog: v1.2.1...v1.4.0