Data Contract for fields within metadataprovider.

For scenarios in which fields within metadataprovider will be serialized and stored and then retrieved to reintialize metadataprovider (rather than recreate the entire object), there needs to be a string data contract for fields within metadataprovider similar to how runtimeconfig.json works.

This issue is created to initiate discussion on what sort of datacontract to create to ensure that if someone takes dependency on fields of metadataprovider, no changes are made that affect backward compatibility.