testkit: Enabling more tests scenarios (#663)
testkit: Enabling more tests scenarios (#663)

* testkit-backend: Implement ResultConsume
* testkit-backend: Implement TransactionRollback
neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver