Automatically add default values for optional types about papyrus

[joshuawright11]

Hey @lyricalsoul! Thanks for the issue and for looking into this - lack of default values is a major pain point. Is the modified @API macro you made adding default values to the protocol in an extension or to the generated concrete type?

i.e. would the default values apply only to direct usages of the struct MessageSenderAPI from above? Or any use of the protocol MessageSender (assuming your example function is in a protocol called MessageSender).

Ideally it would be the protocol so that mocked interfaces could have the same default value API, perhaps via an extension?