Use hardhat-exposed to reduce the need for mocks (#3666)

Co-authored-by: Francisco <fg@frang.io>

test/helpers/chainid.js

@@ -0,0 +1,10 @@
+const hre = require('hardhat');
+
+async function getChainId () {
+  const chainIdHex = await hre.network.provider.send('eth_chainId', []);
+  return new hre.web3.utils.BN(chainIdHex, 'hex');
+}
+
+module.exports = {
+  getChainId,
+};