Gracefully handle errors when loading the record #26
Description
If the recordUrl provided to the viewer doesn't resolve to a JSON record, or that record isn't in Aardvark format, we should do something helpful so the user knows that.
One option is to immediately render a Dialog with some error information. I think it'd be helpful to distinguish between the above cases (HTTP request failed vs. record couldn't be parsed vs. record was parsed but it wasn't Aardvark).