MDEV-17554 Auto-create new partition for system versioned tables with history partitioned by INTERVAL/LIMIT

When there are E empty partitions left, auto-create N new empty
partitions for SYSTEM_TIME partitioning rotated by INTERVAL/LIMIT and
marked by AUTO_INCREMENT keyword. Syntax change: AUTO_INCREMENT
keyword (or shorter AUTO may be used instead) after LIMIT/INTERVAL
clause.

CREATE OR REPLACE TABLE t (x INT) WITH SYSTEM VERSIONING
PARTITION BY SYSTEM_TIME LIMIT 100000 AUTO_INCREMENT;

CREATE OR REPLACE TABLE t (x INT) WITH SYSTEM VERSIONING
PARTITION BY SYSTEM_TIME INTERVAL 1 WEEK AUTO_INCREMENT;

The current revision implements hard-coded values of 1 for E and N. As
well as auto-creation threshold MinInterval = 1 hour, MinLimit = 1000.

The name for newly added partition will be first chosen as "pX", where
X is partition number and "p" is hard-coded name prefix. If this name
is already occupied, the X will be incremented until the resulting
name will be free to use.

ALTER TABLE ADD PARTITION is now always fast. If there some history
partition overflow occurs manual ALTER TABLE REBUILD PARTITION is
needed.