feat: Chainlink Emergency Oracle update for ccc rev 4

Author: sendra

src/contracts/revisions/update_to_rev_4/CrossChainControllerWithEmergencyMode.sol

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.8;
+
+import {CrossChainControllerWithEmergencyMode} from '../../CrossChainControllerWithEmergencyMode.sol';
+import {IReinitialize} from './IReinitialize.sol';
+
+/**
+ * @title CrossChainControllerWithEmergencyModeUpgradeRev4
+ * @author BGD Labs
+ * @notice Contract inheriting from CrossChainControllerWithEmergencyMode with the addition of re initialization method
+ * @dev reinitializer is not used on parent CrossChainController, so this contract is needed to be able to initialize CCC with a new implementation
+ * @dev it initializes the new implementation with the addition of the required Chainlink Emergency Oracle address
+ */
+contract CrossChainControllerWithEmergencyModeUpgradeRev4 is
+  CrossChainControllerWithEmergencyMode,
+  IReinitialize
+{
+  constructor(address clEmergencyOracle) CrossChainControllerWithEmergencyMode(clEmergencyOracle) {}
+
+  /// @inheritdoc IReinitialize
+  function initializeRevision(address chainlinkEmergencyOracle) external reinitializer(4) {
+    _updateCLEmergencyOracle(chainlinkEmergencyOracle);
+  }
+}

src/contracts/revisions/update_to_rev_4/IReinitialize.sol

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+/**
+ * @title IReinitialize
+ * @author BGD Labs
+ * @notice interface containing re initialization method
+ */
+interface IReinitialize {
+  /**
+   * @notice method called to re initialize the proxy
+   * @param chainlinkEmergencyOracle address of the Chainlink emergency oracle
+   */
+  function initializeRevision(address chainlinkEmergencyOracle) external;
+}