Add many=True kwarg to get_edx_api_data to modify empty return value; make resource_id checks slightly more strict

These changes unify four different approaches to JWT creation, moving the core of the AccessTokenView to a general-purpose JwtBuilder class. This utility class defaults to using the system's JWT configuration, but it will allow overriding of the signing key and audience claim to support those clients which still require this. Part of ECOM-4566.

ECOM-2361

This will be used to retrieve data for the program detail page. Part of ECOM-4415.

ECOM-3278

ECOM-3015

ECOM-3278

ECOM-3015