Propose an API to source descriptor mappings

The concept of sourcing field mappings was presented and proposed at the Tech Congress session on Descriptors https://techdocs.ed-fi.org/display/EE/Managing+Descriptors%2C+Setting+Expectations+and+Certification+Implications

To move that work forward, we want to propose an API data model structure to support sourcing descriptor mappings as data.

The initial, canonical use case for this is:

As an LEA I want to be able to receive my student information systems data with my local enumerations intact so that I retain fidelity to my local school district processes and classifications and therefore maximize the potential for (and minimize loss for) analytics using that data. But I also want to be able to source the state-level view of the data – including state descriptors – as measuring compliance to state policies is also a critical aspect of my operations.

This concept has emerged in field work (Texas project) and earlier aspects of Ed-Fi even included aspects of this concept (Types vs Descriptors were in part an attempt to navigate different spheres, but the concept was not open enough).

Also to consider as a primary source are the designs for descriptor mapping in SIS systems, so that exchange over API can be optimized.