Refactor partition auto-creation via direct fast_alter_partition_table()

Asynchronous solution of MDEV-17554 has drawback of race condition:

1. statement thread unlocks table, finishes execution;
2. table is dropped, new table with same name is created;
3. alter thread tries to add partition to new table.

The worst consequence: new table has additional partition unexpectedly.

Instead of asynchronous thread make direct `fast_alter_partition_table()` call at the finish of DML statement.