Implement NFT case study for hyperchains prototype

[kantai]

We should implement a case study application and document how the application can be spun up in two ways:

1. On the actual Stacks testnet
2. On a local Stacks mocknet

This will require a few different pieces:

• A simple Stacks NFT contract, which exposes an interface that the sample hyperchains contract can invoke
• A counterpart to the Stacks NFT contract for launching on the hyperchain, which exposes the requisite depost and withdraw interfaces.
• An integration test which:
  - Starts a Stacks mocknet node
  - Deploys the sample hyperchain contract to the Stacks node
  - Deploys the Stacks NFT contract
  - Deploys the Hyperchain NFT contract
  - Tests: mint on hyperchain, withdraw to Stacks chain
  - Tests: mint on Stacks chain, deposit to hyperchain

[lgalabru]

A lighter version of http://wyvernprotocol.com could be interesting.

[saralab]

Include Transfers of NFTs within Hyperchains in the use case

[saralab]

Merged, closing this