feat(SpokePoolPeriphery): Support multiple exchanges

contracts/Create2Factory.sol

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+pragma solidity ^0.8.0;
+
+import { Create2 } from "@openzeppelin/contracts/utils/Create2.sol";
+import { Lockable } from "./Lockable.sol";
+
+/**
+ * @title Create2Factory
+ * @notice Deploys a new contract via create2 at a deterministic address and then atomically initializes the contract
+ * @dev Contracts designed to be deployed at deterministic addresses should initialize via a non-constructor
+ * initializer to maintain bytecode across different chains.
+ * @custom:security-contact bugs@across.to
+ */
+contract Create2Factory is Lockable {
+    /// @notice Emitted when the initialization to a newly deployed contract fails
+    error InitializationFailed();
+
+    /**
+     * @notice Deploys a new contract via create2 at a deterministic address and then atomically initializes the contract
+     * @param amount The amount of ETH to send with the deployment. If this is not zero then the contract must have a payable constructor
+     * @param salt The salt to use for the create2 deployment. Must not have been used before for the bytecode
+     * @param bytecode The bytecode of the contract to deploy
+     * @param initializationCode The initialization code to call on the deployed contract
+     */
+    function deploy(
+        uint256 amount,
+        bytes32 salt,
+        bytes calldata bytecode,
+        bytes calldata initializationCode
+    ) external nonReentrant returns (address) {
+        address deployedAddress = Create2.deploy(amount, salt, bytecode);
+        (bool success, ) = deployedAddress.call(initializationCode);
+        if (!success) revert InitializationFailed();
+        return deployedAddress;
+    }
+}

contracts/external/interfaces/IERC20Auth.sol

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.0;
+
+/*
+ * @notice Minimal interface for an EIP-3009 compliant token.
+ * https://eips.ethereum.org/EIPS/eip-3009
+ */
+interface IERC20Auth {
+    /**
+     * @notice Receive a transfer with a signed authorization from the payer
+     * @dev This has an additional check to ensure that the payee's address matches
+     * the caller of this function to prevent front-running attacks. (See security
+     * considerations)
+     * @param from          Payer's address (Authorizer)
+     * @param to            Payee's address
+     * @param value         Amount to be transferred
+     * @param validAfter    The time after which this is valid (unix time)
+     * @param validBefore   The time before which this is valid (unix time)
+     * @param nonce         Unique nonce
+     * @param v             v of the signature
+     * @param r             r of the signature
+     * @param s             s of the signature
+     */
+    function receiveWithAuthorization(
+        address from,
+        address to,
+        uint256 value,
+        uint256 validAfter,
+        uint256 validBefore,
+        bytes32 nonce,
+        uint8 v,
+        bytes32 r,
+        bytes32 s
+    ) external;
+}