MDEV-31503 ALTER SEQUENCE ends up in optimistic parallel slave binlog out-of-order

The OOO error still was possible even after MDEV-31077. This time
it occured through open_table() when the sequence table was not in
the table cache *and* the table was created before the last server
restart.
In such context a internal (read-only) transaction is committed
and it was not blocked from doing a wakeup() call to subsequent
transactions.

Fixed with extending suspend_subsequent_commits() effect for the entirety
of Sql_cmd_alter_sequence::execute().
An elaborated MDEV-31077 test proves the fixes of both failure scenarios.

Also the bug condition suggests a workaround to pre-SELECT sequence
tables before START SLAVE.
Reviewed-by: Brandon Nesterenko <brandon.nesterenko@mariadb.com>