feat(fuzz): cheatcode to populate in-memory corpus

### Component

Forge

### Describe the feature you would like

A straightforward way to allow experimentation without requiring modifying the fuzzer would be to add a cheatcode that takes a hash and have the fuzzer save new hashes into the queue for mutation. It would be similar to IJON (https://github.com/RUB-SysSec/ijon). Then, power uses can define how interesting a state is with a hash (as fine-or-coarse grained as you please)

Basically permanently add an input to the in-memory corpus

### Additional context

_No response_