Support AbortSignal in start(), exec and other long-running calls #1560

What happens

Nothing in the API accepts an AbortSignal.

• start() can spend minutes pulling an image and waiting for readiness. When the test runner times the test out, or the user gives up, the start carries on in the background. The container is still created and stays until Ryuk removes it at process exit.
• The only timeout is the wait strategy's startup timeout. It does not cover the image pull.
• exec has no timeout and cannot be cancelled, so a command that hangs blocks its caller indefinitely.
• DockerComposeEnvironment.up() and GenericContainerBuilder.build() are the same.

Expected

Long-running operations take a signal:

await new GenericContainer(image).start({ signal: AbortSignal.timeout(30_000) });
await container.exec(["pg_dump"], { signal });

On abort the promise rejects with the signal's reason, and whatever was half-created (container, network attachment, Compose project) is stopped and removed.

Where

• start and startContainer in packages/testcontainers/src/generic-container/generic-container.ts
• pull and build in packages/testcontainers/src/container-runtime/clients/image/docker-image-client.ts
• packages/testcontainers/src/wait-strategies/*.ts
• exec in packages/testcontainers/src/container-runtime/clients/container/docker-container-client.ts
• up in packages/testcontainers/src/docker-compose-environment/docker-compose-environment.ts

Notes

• Go passes a context.Context to every call. .NET takes a CancellationToken.
• Related: Support signal from AbortController to stop container creation #1081 asked for this. It was closed when the reporter's underlying problem turned out to be something else.
• A startup deadline is a signal with a timeout. One mechanism can serve both this and Apply one startup deadline from container start to ready #1582.

Dependencies

• Stack on Pass the started container to WaitStrategy.waitUntilReady #1558: both change the wait strategy interface. Change it once, in the same major.
• Coordinate with Extend exec: reject on failure, stdin, streaming output and a timeout #1548: exec gains a timeout there. Make the two agree.
• Coordinate with Apply one startup deadline from container start to ready #1582: the deadline can be carried by the same signal.