Cannon Go e2e tests

[norswap]

Create e2e tests of the same kind as we have in Bedrock, in order to test L2 block validation on L2.

[norswap]

Something to consider: having some kind of transaction generator in order to have something meaningful to validate.

It seems quite hard to do well, given that we would need to deploy some smart contracts.

One possibility would be to replay some existing set of transactions from a genesis. The start of L1 mainnet history? TBD if the complexity of doing that is actually realistic.

[norswap]

The first step of this will be refactor minigeth/main.go so that it has an entry point with proper parameters and not only taking parameter specified as command line arguments / environment variables.

[protolambda]

Cannon now runs some example Go programs, that cover the pre-image functionality that is also used by the L2 program, which is otherwise out of scope. Minigeth is no longer part of Cannon. With the op-program e2e testing we can revisit the test approach. Closing this.