Title: Difference between Schema.optional and Schema.UndefinedOr (and why annotations behave diff...

Schema.optional(Schema.String)
// and
Schema.UndefinedOr(Schema.String)

const SomethingIDWithoptional = Schema.optional(Schema.String).pipe(Schema.annotations({identifier: 'something id'})) // ts error
const SomethingIDWithUndefined = Schema.UndefinedOr(Schema.String).pipe(Schema.annotations({identifier: 'something id'})) // works fine!