test: stop mocking and use real verifiers

[LHerskind]

This pr addresses a few oddities I ran into when trying out your template.

1. The testFail have deprecated in foundry with the stable releases, so updated to be more specific there.
2. The tests just mocked a fake verifier saying yes so I updated it to instead deploy the real verifiers and then use those for the checks. I know you prefer the gateway, but with the split it seemed useful to be very explicit about the verifier.

Saw some oddities with the error naming in groth16 and created an issue in succinctlabs/sp1-contracts#42