End-to-end test: Resume from savepoint

User usually take a savepoint and want to resume from it. In order to verify that Flink supports this feature, we should add an end-to-end test which scripts this behavior. We should use the general purpose testing job FLINK-8971 with failures disabled for that.

The end-to-end test should do the following:

• Submit FLINK-8971 job
• Verify that the savepoint is there
• Cancel job and resume from savepoint
• Verify that job could be resumed
• Use different StateBackends: RocksDB incremental async/sync, RocksDB full async/sync, FsStateBackend aysnc/sync