SDK package: Hook up remaining Transfer types

[jurevans]

Since the build functions for transfer and the transfer types themselves have been split from a single type, we need to add definitions to our SDK package to support these.

• Hook up Shielding transfer function
• Hook up Unshielding transfer function
• Ensure we can serialize/deserialize these (there may be some things to do in the Transfer type, but looks like it's complete as is)
• MASP Params will need to be loaded to fully test
• Generate updated documentation