[Tracking] backing store support - Go

[baywet]

pending on #413

Today the generation logic does not support providing a backing store. The abstractions library also does not have the different constructs:

• update the abstraction library to provide the serialization factories proxies, the callbacks, the backing store interface, and the in memory implementation (see other languages)
• update the generation logic to support re-routing the accessors to a backing store (some of the logic is already in place)
• update the serialization library to leverage the callbacks during serialization/deserialization
  AB#10604