Explore options for adding support for contract extensions

[leighmcculloch]

There are several patterns out in the wild for how to implement contract extensions.

Contract extensions is the term I'm using to refer to contract that can be reused, extended, or functionality partially replaced.

We should explore if the SDK should add a native ability to support extending contracts, either adopting a pattern already in use as is as a library, or internalising / embedding it.