feat(MemberOrder, MemberOrderHistory, MemberOrderService, OrdersPanel): add paidConfirmed field and update related logic

- Introduced a new boolean field `paidConfirmed` in MemberOrder and MemberOrderHistory models to track payment confirmation status.
- Updated serialization functions in MemberOrderService to include `paidConfirmed` in order and history entries.
- Enhanced OrdersPanel component to allow users to set and display the `paidConfirmed` status for orders.
- Added localization support for the new `paidConfirmed` label in German.
- Adjusted related logic to ensure proper handling of the `paidConfirmed` state throughout the application.

backend/models/MemberOrder.js

@@ -54,6 +54,12 @@ const MemberOrder = sequelize.define('MemberOrder', {
     type: DataTypes.DECIMAL(10, 2),
     allowNull: false,
     defaultValue: 0
+  },
+  paidConfirmed: {
+    type: DataTypes.BOOLEAN,
+    allowNull: false,
+    defaultValue: false,
+    field: 'paid_confirmed'
   }
 }, {
   underscored: true,

backend/models/MemberOrderHistory.js

@@ -52,6 +52,12 @@ const MemberOrderHistory = sequelize.define('MemberOrderHistory', {
     type: DataTypes.DECIMAL(10, 2),
     allowNull: false,
     defaultValue: 0
+  },
+  paidConfirmed: {
+    type: DataTypes.BOOLEAN,
+    allowNull: false,
+    defaultValue: false,
+    field: 'paid_confirmed'
   }
 }, {
   underscored: true,