feat(`cheatcodes`): access broadcast artifacts

[yash-atreya]

Motivation

Builds upon #9098

Closes #4732 + Closes #9083

Solution

// Returns the most recent broadcast for the given contract on `chainId` matching `txType`.
function getBroadcast(string memory contractName, uint64 chainId, BroadcastTxType txType) external returns (BroadcastTxSummary memory);

//  Returns all broadcasts for the given contract on `chainId` with the specified `txType`.
//  Sorted such that the most recent broadcast is the first element, and the oldest is the last. i.e descending order of BroadcastTxSummary.blockNumber.
function getBroadcasts(string memory contractName, uint64 chainId, BroadcastTxType txType) external returns (BroadcastTxSummary[] memory);

// Returns all broadcasts for the given contract on `chainId`.
// Sorted such that the most recent broadcast is the first element, and the oldest is the last. i.e descending order of BroadcastTxSummary.blockNumber.
function getBroadcasts(string memory contractName, uint64 chainId) external returns (BroadcastTxSummary[] memory);

• [ ] Tests