Get URLs for fetching bytes from multiple objects with an optional Passport(s)

Returns an array of URL objects that can be used to fetch the bytes of multiple DrsObjects.
This method only needs to be called when using an AccessMethod that contains an access_id
(e.g., for servers that use signed URLs for fetching object bytes).
Currently this is limited to use passports (one or more) or a single bearer token,
so make sure your bulk request is for objects that all use the same passports/token.