feat(forge): forge flatten

[brockelmore]

Add an flatten command that would grab a contract and its dependencies and print to stdout. With the other issues around verify-contract, this would provide at the very least users the ability to get forge's best guess at what the compiler is doing with the standard-json input and allow a user to tweak and manually verify if needed. Also I imagine this will surface issues around verify-contract for debugging it.

i.e.:

pragma solidity ^0.8.0;

import "./ContractDep.sol";

contract Contract is ContractDep {
}

would print out:

pragma solidity ^0.8.0;
contract ContractDep {
     uint256 myVar;
}
contract Contract is ContractDep {
}

[gakonst]

I think this is typically called flatten? Agreed otherwise that it can be useful.

[lucas-manuel]

Yeah this would be analogous to hevm flatten

[brockelmore]

sure i was basing it off of cargo expand didnt know hevm flatten existed. Agree flatten makes more sense

[mattsse]

closed #506