Refactor/structs replace jsonvalue

[yellowHatpro]

• Replaced JsonValue with structs

[RustyNova016]

You may want to remove some of those options. For fields that aren't optional you can just put the type and not have to worry about it being an option ;) (Although you need to be sure they aren't optional, which isn't always clear cough musicbrainz API)

[yellowHatpro]

@RustyNova016 haha, thanks for the suggestion. Sorry I was inactive last week, so couldn't do much. I was doubtful about the types, so I ended up making them all optional.