nullability improvements, documentation improvements

This is a Major overhaul of the Package.
It implements nullable types for all endpoints. It is likely to require code changes or otherwise at least produces plentiful null value compiler warnings.

Enhanced features:

• Improved handling of null parameters: The RPC interface now properly handles null input parameters. This ensures that the application does not crash or cause unintended behavior when null is passed.
• RPC Parameter nullable: All RPC parameter objects are now nullable. This helps to prevent malformed requests and enhances the robustness of our API communication.
• Added null checks in RPC methods: Methods like BatchUpdate_Async now check if their required parameters are null before executing. This allows us to fail early and return a useful error message instead of causing an unexpected exception at runtime.
• Fixed potential NullReferenceExceptions
• Expanded XML Comments: We have vastly added or expanded XML comments to several classes and methods. These comments serve as in-code documentation and provide useful context and explanations for developers.
• All compiler warnings within the package have been resolved
  Please refer to the documentation and updated code comments for more detailed information about these updates. As always, feel free to report any issues or provide feedback on these changes.

1.6.2

added hashset and dictionary to the metadata. Please use the update functions going forward.

1.6.1 - chip 0007 std

this release features the chip-0007 std and should be compatible with newer chia versions until a new chip std. arises.