Etherscan broadcast api might get rate limited without throwing error

[ghost]

It was possible for etherscan to seemly get an okay API response but have a result of "Max rate limit reached, please use API Key for higher rate limit" instead of a transaction ID.

We should check for their standard way of doing error handling:

code: 200
body: {
    "status": "0",
    "message": "NOTOK",
    "result": "Max rate limit reached, please use API Key for higher rate limit"
}