Add arbitration cost forwarding and feeForJuror param

* refactor(gateway): add RAB pragma and use internal functions for the bridge

* feat(gateway): add forwarding for arbitrationCost

* feat(gateway): add and use feeForJuror param by governor

* fix(gateway): update disputeHash calculation

* refactor(gateway): rename some functions

* refactor(gateway): rename xdai -> gnosis

* refactor(gateway): getSubmissionPrice -> bridgingCost

* refactor(gateway): reorder struct members

* refactor: rename gateways

Author: shalzz

contracts/src/bridge/IL1Bridge.sol

@@ -2,7 +2,11 @@
 
 pragma solidity ^0.8.0;
 
-interface IL1Bridge {
+/**
+ * This is essentially an interface but defined as an abstract contract
+ * to declare functions as internal instead of as external
+ */
+abstract contract IL1Bridge {
     /**
      * Sends an arbitrary message from one domain to another.
      *
@@ -24,9 +28,9 @@ interface IL1Bridge {
         bytes memory _calldata,
         uint256 _maxGas,
         uint256 _gasPriceBid
-    ) external payable returns (uint256);
+    ) internal virtual returns (uint256);
 
-    function getSubmissionPrice(uint256 _calldatasize) external view returns (uint256);
+    function bridgingCost(uint256 _calldatasize) internal view virtual returns (uint256);
 
-    function onlyAuthorized() external;
+    function onlyCrossChainSender() internal virtual;
 }

contracts/src/bridge/IL2Bridge.sol

@@ -2,14 +2,18 @@
 
 pragma solidity ^0.8.0;
 
-interface IL2Bridge {
+/**
+ * This is essentially an interface but defined as an abstract contract
+ * to declare functions as internal instead of as external
+ */
+abstract contract IL2Bridge {
     /**
      * Sends an arbitrary message from one domain to another.
      *
      * @param _calldata The L1 encoded message data.
      * @return Unique id to track the message request/transaction.
      */
-    function sendCrossDomainMessage(bytes memory _calldata) external returns (uint256);
+    function sendCrossDomainMessage(bytes memory _calldata) internal virtual returns (uint256);
 
-    function onlyAuthorized() external;
+    function onlyCrossChainSender() internal virtual;
 }

contracts/src/bridge/arbitrum/ArbL1Bridge.sol

@@ -1,5 +1,13 @@
 // SPDX-License-Identifier: MIT
 
+/**
+ *  @authors: [@shalzz]
+ *  @reviewers: []
+ *  @auditors: []
+ *  @bounties: []
+ *  @deployments: []
+ */
+
 pragma solidity ^0.8.0;
 
 import "./interfaces/IInbox.sol";
@@ -41,8 +49,8 @@ contract ArbL1Bridge is IL1Bridge {
         bytes memory _calldata,
         uint256 _maxGas,
         uint256 _gasPriceBid
-    ) external payable returns (uint256) {
-        uint256 baseSubmissionCost = getSubmissionPrice(_calldata.length);
+    ) internal override returns (uint256) {
+        uint256 baseSubmissionCost = bridgingCost(_calldata.length);
         require(msg.value >= baseSubmissionCost + (_maxGas * _gasPriceBid));
 
         uint256 ticketID = inbox.createRetryableTicket{value: msg.value}(
@@ -60,12 +68,12 @@ contract ArbL1Bridge is IL1Bridge {
         return ticketID;
     }
 
-    function getSubmissionPrice(uint256 _calldatasize) public view returns (uint256) {
+    function bridgingCost(uint256 _calldatasize) internal view override returns (uint256) {
         (uint256 submissionCost, ) = arbRetryableTx.getSubmissionPrice(_calldatasize);
         return submissionCost;
     }
 
-    function onlyAuthorized() external {
+    function onlyCrossChainSender() internal override {
         IOutbox outbox = IOutbox(inbox.bridge().activeOutbox());
         address l2Sender = outbox.l2ToL1Sender();
         require(l2Sender == l2Target, "Only L2 target");

contracts/src/bridge/arbitrum/ArbL2Bridge.sol

@@ -1,5 +1,13 @@
 // SPDX-License-Identifier: MIT
 
+/**
+ *  @authors: [@shalzz]
+ *  @reviewers: []
+ *  @auditors: []
+ *  @bounties: []
+ *  @deployments: []
+ */
+
 pragma solidity ^0.8.0;
 
 import "./interfaces/IArbSys.sol";
@@ -23,14 +31,14 @@ contract ArbL2Bridge is IL2Bridge {
      * @param _calldata The L1 encoded message data.
      * @return Unique id to track the message request/transaction.
      */
-    function sendCrossDomainMessage(bytes memory _calldata) external returns (uint256) {
+    function sendCrossDomainMessage(bytes memory _calldata) internal override returns (uint256) {
         uint256 withdrawalId = arbsys.sendTxToL1(l1Target, _calldata);
 
         emit L2ToL1TxCreated(withdrawalId);
         return withdrawalId;
     }
 
-    function onlyAuthorized() external {
+    function onlyCrossChainSender() internal override {
         require(msg.sender == AddressAliasHelper.applyL1ToL2Alias(l1Target), "Only L1 target");
     }
 }

contracts/src/bridge/xdai/xDaiL1Bridge.sol renamed to contracts/src/bridge/gnosis-chain/GnosisL1Bridge.sol

@@ -1,12 +1,20 @@
 // SPDX-License-Identifier: MIT
 
+/**
+ *  @authors: [@shalzz]
+ *  @reviewers: []
+ *  @auditors: []
+ *  @bounties: []
+ *  @deployments: []
+ */
+
 pragma solidity ^0.8.0;
 
 import "./interfaces/IAMB.sol";
 
 import "../IL1Bridge.sol";
 
-contract xDaiL1Bridge is IL1Bridge {
+contract GnosisL1Bridge is IL1Bridge {
     address public l2Target;
     IAMB amb;
 
@@ -19,7 +27,7 @@ contract xDaiL1Bridge is IL1Bridge {
         bytes memory _calldata,
         uint256 _maxGas,
         uint256 _gasPriceBid
-    ) external payable returns (uint256) {
+    ) internal override returns (uint256) {
         bytes32 id = amb.requireToPassMessage(l2Target, _calldata, amb.maxGasPerTx());
         return uint256(id);
     }
@@ -28,13 +36,13 @@ contract xDaiL1Bridge is IL1Bridge {
      * @dev The xDai bridge gas cost doesn't depend on the calldata size
      *
      */
-    function getSubmissionPrice(
+    function bridgingCost(
         uint256 /* _calldatasize */
-    ) public view returns (uint256) {
+    ) internal view override returns (uint256) {
         return 0;
     }
 
-    function onlyAuthorized() external {
+    function onlyCrossChainSender() internal override {
         require(msg.sender == address(amb), "Only AMB allowed");
         // require(amb.messageSourceChainId() == foreignChainId, "Only foreign chain allowed");
         require(amb.messageSender() == l2Target, "Only foreign gateway allowed");

contracts/src/bridge/xdai/xDaiL2Bridge.sol renamed to contracts/src/bridge/gnosis-chain/GnosisL2Bridge.sol

@@ -1,12 +1,20 @@
 // SPDX-License-Identifier: MIT
 
+/**
+ *  @authors: [@shalzz]
+ *  @reviewers: []
+ *  @auditors: []
+ *  @bounties: []
+ *  @deployments: []
+ */
+
 pragma solidity ^0.8.0;
 
 import "./interfaces/IAMB.sol";
 
 import "../IL2Bridge.sol";
 
-contract xDaiL2Bridge is IL2Bridge {
+contract GnosisL2Bridge is IL2Bridge {
     address public l1Target;
     IAMB amb;
 
@@ -15,12 +23,12 @@ contract xDaiL2Bridge is IL2Bridge {
         amb = _amb;
     }
 
-    function sendCrossDomainMessage(bytes memory _calldata) external returns (uint256) {
+    function sendCrossDomainMessage(bytes memory _calldata) internal override returns (uint256) {
         bytes32 id = amb.requireToPassMessage(l1Target, _calldata, amb.maxGasPerTx());
         return uint256(id);
     }
 
-    function onlyAuthorized() external {
+    function onlyCrossChainSender() internal override {
         require(msg.sender == address(amb), "Only AMB allowed");
         // require(amb.messageSourceChainId() == homeChainId, "Only home chain allowed");
         require(amb.messageSender() == l1Target, "Only home gateway allowed");