feat: purchase tracker logs currency

Author: hudsonhrh

src/IPurchaseTracker.sol

@@ -2,9 +2,11 @@
 pragma solidity ^0.8.20;
 
 interface IPurchaseTracker {
-    function recordPurchase(bytes32 paymentId, address seller, address buyer, uint256 amount) external;
+    function recordPurchase(bytes32 paymentId, address seller, address buyer, uint256 amount, address currency) external;
     function getPurchaseCount(address recipient) external view returns (uint256);
     function getPurchaseAmount(address recipient) external view returns (uint256);
     function getSalesCount(address recipient) external view returns (uint256);
     function getSalesAmount(address recipient) external view returns (uint256);
+    function getPurchaseAmountByCurrency(address recipient, address currency) external view returns (uint256);
+    function getSalesAmountByCurrency(address recipient, address currency) external view returns (uint256);
 }

src/PaymentEscrow.sol

@@ -82,7 +82,7 @@ contract PaymentEscrow is PaymentEscrowAdmins, HasSecurityContext, IEscrowContra
      * @notice Constructor.
      * @param securityContext Contract which will define & manage secure access for this contract.
      * @param settings_ Address of contract that holds system settings.
-     * @param autoRelease Determines whether new payments automatically have the receiver’s assent.
+     * @param autoRelease Determines whether new payments automatically have the receiver's assent.
      * @param _purchaseTracker Address of the PurchaseTracker singleton.
      */
     constructor(
@@ -317,7 +317,7 @@ contract PaymentEscrow is PaymentEscrowAdmins, HasSecurityContext, IEscrowContra
                 emit EscrowReleased(paymentId, amountToPay, fee);
 
                 if (address(purchaseTracker) != address(0)) {
-                    purchaseTracker.recordPurchase(paymentId, payment.receiver, payment.payer, amountToPay);
+                    purchaseTracker.recordPurchase(paymentId, payment.receiver, payment.payer, amountToPay, payment.currency);
                 }
             }
         }