Minimalist A/B testing framework

[cylewitruk]

A/B testing application.
To be used for testing and comparing chainstate transaction results using the current interpreter vs. the new wasm runtime by replaying all state from genesis to chain tip, including contract installs and executions.

Tracked in issues:

• Initialize new chainstate
• Extract transactions and contract installs/calls from existing chainstate
• Process STX transactions
• Install contracts from chainstate
• Execute contracts using Interpreter
• Execute contracts using Wasm
• Ability to create environment snapshots
• more coming...

[smcclellan]

@cylewitruk Is this still needed?

[cylewitruk]

It's still an active project but I'm planning on moving it out of this repo to testing-tools, so it can be closed here.