ERDDAP support for Data Product Registration

Part of [OOIION-1285](https://jira.oceanobservatories.org/tasks/browse/OOIION-1285)

[COI-SMOKE](http://buildbot.oceanobservatories.org:8010/builders/coi_smoke/builds/2867)
[DM Test-Suite](http://buildbot.oceanobservatories.org:8010/builders/coi_any/builds/104)