Added a ToStringRole to summarize the model items (for tool tip and QR code).

model/tablemodel.cpp

@@ -76,6 +76,8 @@ QVariant TableModel::data(const QModelIndex& index, int role) const {
     case AmountRole:
     case FactorRole:
       return m_items.at(row)->data(role);
+    case ToStringRole:
+      return m_items.at(row)->toString();
   }
 
   return QVariant();