feat: add support for nested transaction rollbacks via savepoints in sql #11710

Job	Run time
Test vitess_5_7 (graphql) on Linux	1m 41s
Test vitess_5_7 (json) on Linux	1m 39s
Test vitess_8_0 (graphql) on Linux	1m 40s
Test vitess_8_0 (json) on Linux	1m 51s
Test postgres15 (graphql) on Linux	13m 35s
Test postgres15 (json) on Linux	16m 58s
Test mssql_2022 (graphql) on Linux	7m 50s
Test mssql_2022 (json) on Linux	7m 52s
Test mongodb_4_2 (graphql) on Linux	3m 11s
Test mongodb_4_2 (json) on Linux	4m 22s
Test cockroach_23_1 (graphql) on Linux	26m 56s
Test cockroach_23_1 (json) on Linux	26m 20s
Test cockroach_22_2 (graphql) on Linux	20m 10s
Test cockroach_22_2 (json) on Linux	15m 49s
Test cockroach_22_1_0 (graphql) on Linux	18m 25s
Test cockroach_22_1_0 (json) on Linux	14m 54s
	3h 3m 13s

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