feat: add endpoint and logic for retrieving transaction chart data, including SQL queries, models, and service integration

internal/mapper/dashboard_mapper.go

@@ -58,3 +58,11 @@ func ToDomainAnomalyItem(r db.GetAnomalyItemsRow) models.AnomalyItem {
 		ComponentUnit: r.ComponentUnit,
 	}
 }
+
+func ToDomainTransactionChartRow(r db.GetTransactionChartDataRow) models.TransactionChartRow {
+	return models.TransactionChartRow{
+		Date:            r.Date.Time,
+		TransactionType: string(r.TransactionType),
+		TotalQuantity:   r.TotalQuantity,
+	}
+}