recalculate long unique hash in Write_rows_log_event
and Update_rows_log_event.

normally generated columns (stored and indexed virtual)
are deterministic and their values don't need to be recalculated
on the slave as they're already present in the row image.
but the long unique hash function was changed in MDEV-27653,
so a row event from the old master will have the old hash,
but a table created on the new slave will need a new hash.