EtherscanProvider: add support for avalanche network and fuji testnet network

[venturars]

I would like to be able to list all the transactions that a user has made in my contract using the getHistory method

Code Example

const startBlock = 3135808;
const endBlock = 5091477;

provider = provider = new ethers.providers.EtherscanProvider("avalanche");

const history = await provider.getHistory("0x00000000000C2E074eC69A0dFb2997BA6C7d2e1e", startBlock, endBlock);

console.log(history);

[ricmoo]

You can easily sub-class the EtherscanProvider and just override this method to try it out. :)