Port over integration tests from monorepo

[mslipper]

Now that sequencing is nearly ready, we can start porting over integration tests from the monorepo. The first set we can port over include:

• [ ] Deposits
• [ ] Simple sends
• [ ] Contract interactions
  • [ ] Uniswap
  • [ ] ERC20
  • [ ] ERC721

[tynes]

At what point does the specs repo turn into the monorepo? Should the specs repo contain specs and the monorepo contain code? This would be easier to delineate once all of the prototyping is done

[norswap]

I think we'd like it to contain both spec & code, so they can be kept in sync (updated by the same PR into main branch from a feature branch).