add option to load fork state

[prat-gpt]

No description provided.

[ElliotFriedman]

    function run() public {
        if (useOpsRepo) {
            vm.loadAlloc("path/to/state.json");
            _readSuperchainRegistry();
        } else {
            // Read the superchain registry and save the addresses to the Artifacts contract.
            _readSuperchainRegistry();
            // Now deploy the updated OPCM and implementations of the contracts
            _deployNewImplementations();
        }

        // Now upgrade the contracts (if the config is set to do so)
        if (cfg.useUpgradedFork()) {
            require(!useOpsRepo, "ForkLive: cannot upgrade and use ops repo");
            console.log("ForkLive: upgrading");
            _upgrade();
        } else if (useOpsRepo) {
            console.log("ForkLive: using ops repo to upgrade");
        }
    }

open PR against mono repo