Date/time range convenience

For range-capable date/time parameters, in addition to giving an ISO string or a range string, support passing an array of two: ISO strings, native Date objects, moment.js moment objects
or Luxon DateTime objects.

Also support passing in a Luxon Interval object, and adjusting for the end of Luxon Interval objects being exclusive but the end of Sierra API ranges being inclusive.

Support open-ended ranges.

Similarly for range-capable date parameters, except the time part is truncated for these.

This doesn't create a dependency on either the moment.js or Luxon libraries. Duck-typing is used to detect moement.js and Luxon objects and convert them to ISO strings. There is a dev dependency on these in order to use these objects for testing.