Always stop E2E engine containers during teardown

Flink, Spark, and SeaTunnel teardown executed an in-container rm before stopping engine containers. If a container never started or had already died, that command threw and skipped later stops and host cleanup. A leaked Flink JobManager could retain the shared jobmanager alias, attract the next test's TaskManager, and leave the new job waiting until timeout.

Adds a shared stopContainersAndDeleteVolume helper that treats in-container cleanup as best effort, stops each container independently, always attempts host-directory deletion, preserves the first real stop or delete failure with later failures suppressed, and restores interrupt status when required.

• Prevents one failed engine container from leaking its sibling containers into subsequent E2E cases.
• Removes a shared-network alias collision that could turn one startup failure into a later, difficult-to-diagnose workflow hang.
• Applies the same teardown guarantees to Flink, Spark, and the SeaTunnel Zeta engine through one reusable helper.
• Keeps cleanup failures observable while distinguishing best-effort in-container removal from failures to stop containers or delete host resources.
• Changes test infrastructure only; no production engine, connector, checkpoint, protocol, or user configuration behavior was modified.

• All 51 seatunnel-e2e-common unit tests passed on JDK 8 and JDK 11, including not-running containers, cleanup exceptions, stop failures, suppressed failures, and interrupt restoration.
• Real-container trials recovered from killed Spark, Zeta, and Flink containers and successfully ran the next job; the prior Flink path leaked its first JobManager in 11 of 11 runs, while the repaired revision completed teardown in 12 of 12 runs.
• An Apache SeaTunnel member approved the final authored change, and all four current hosted checks pass. Linux host-directory ownership remains an observable follow-up rather than a claimed solved condition.