fix(types): adapt type definition of dataOrUpdater in setQueryData (#540)

since the updater receives `T | undefined`, it is difficult to construct a `T` from that. oldData can legitimately be `undefined`, but since `getQueryData` can also return `undefined` at any point, it makes more sense to have the updater be able to return `undefined` as well, which also means that `data` itself can be `undefined`