Epic: Simulating Simulations

[nventuro]

We want to be able to simulate a transaction that requires approval from an account contract (i.e. checks that involve the signing key, such as authwits), without providing any of these. This would let us know what the result of a transaction would be before signing anything. As a side-effect we'd learn in advance all of the authwits that we need to sign before execution begins, which means we don't need interactivity from the PXE and the signer (because we've pre-signed everything).

More context: https://forum.aztec.network/t/simulating-simulations/2218

### Tasks
- [ ] Hack the account contract so that we skip all checks and make them pass
- [ ] Collect the signatures and authwits that were skipped and present them along with the TX results
- [ ] Make the authwit target pregimage available when signing
- [ ] Remove the authwith boilerplate via macros
- [ ] Remove the need to pass a nonce from the caller