MDEV-11934: MariaRocks: Group Commit with binlog
MDEV-11934: MariaRocks: Group Commit with binlog

Port the previous patch:
- Implement MariaDB's Group Commit API. This is a first
   attempt which lacks the expected performance.

To newer MariaDB (which includes newer MyRocks)

natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2