Summary:
`WithDefault` appears not to be required to be prefixed with `?` because it's option value per se.
Fixed tests, removed `?` where needed, updated snapshots and review them. Added mechanism fro throwing error when `?WithDefault` found. Add tests for it.
Reviewed By: rubennorte
Differential Revision: D16048463
fbshipit-source-id: f55ed7454aacf0b8c42944a9b5c1037ad1b360fe