Create API and simple interface for searching/viewing mapping data

[gtsueng]

Is your feature request related to a problem? Please describe.
Eventually, it would be useful to be able to search for a property and see how it maps in different schema

Describe the solution you'd like
We have a schema for metadata crosswalks and some sample data. It would be good to eventually be able to register mappings, search, and explore them

Describe alternatives you've considered
We have been using google spreadsheets

[gtsueng]

This not urgent, I'm just creating a ticket for this so it can be taken into consideration for future designs.