fix: custom data source creation failed in enterprise ClickHouse

If the GROUP BY field is in `( )`, it will be considered that the GROUP BY is an entire tuple, not multiple fields.
The field to be SELECTed is not in the field list of GROUP BY, and a query error occurs.

server/ingester/datasource/handle.go

@@ -405,7 +405,7 @@ func MakeMVTableCreateSQL(t *ckdb.Table, db, dstTable, aggrSummable, aggrUnsumma
  return fmt.Sprintf(`CREATE MATERIALIZED VIEW IF NOT EXISTS %s TO %s
  AS SELECT %s
  FROM %s
- GROUP BY (%s)
+ GROUP BY %s
  ORDER BY (%s)`,
  tableMv, tableAgg,
  strings.Join(columns, ",\n"),