add test to ensure SET STATEMENT FOR MariaDB specific SQL works prope… #1701

Job	Run time
checkstyle	32s
e2e_tests (latest, 7.2)	15m 49s
unit_tests (latest, 7.2, singlesite)	15m 30s
e2e_tests (latest, 8.1)	16m 20s
unit_tests (latest, 7.2, multisite)	12m 23s
e2e_tests (trunk, 7.2)	15m 52s
e2e_tests (trunk, 8.1)	10m 15s
unit_tests (latest, 8.1, singlesite)	16m 3s
unit_tests (latest, 8.1, multisite)	13m 58s
unit_tests (5.2, 7.2, singlesite)	11m 56s
unit_tests (5.2, 7.2, multisite)	12m 37s
	2h 21m 15s

Provide feedback