feat(job): implement moveToWaitingChildren for sandboxed jobs

[shichongrui]

Why

moveToWaitingChildren is not implemented on sandboxed jobs. The docs don't explain this and from what I could see there was no reason for it not to be other than that it just wasn't implemented there.

How

I followed the same approach that the moveToDelayed function uses in a sandboxed job to send commands back to the parent process to actually execute the functionality.

Additional Notes (Optional)

I did not see any tests for moveToDelayed that tested from within a sandboxed process so I wasn't sure if there was somewhere to add tests for this functionality.

I've done a yarn pack and then untarred it in a local bullmq project and confirmed that it was working though.

Fixes #3230

[Copilot]

Pull Request Overview

This PR implements the moveToWaitingChildren functionality for sandboxed jobs by adding a new enum value and handling the command in both the sandbox and child-processor modules.

• Added MoveToWaitingChildren to the ParentCommand enum.
• Updated sandbox.ts and child-processor.ts to proxy moveToWaitingChildren commands.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/enums/parent-command.ts	Added the MoveToWaitingChildren enum
src/classes/sandbox.ts	Added a case to handle MoveToWaitingChildren commands in the sandbox
src/classes/child-processor.ts	Introduced a proxy function to forward moveToWaitingChildren commands

Comments suppressed due to low confidence (2)

src/classes/sandbox.ts:55

• Add tests covering the MoveToWaitingChildren command handling in sandbox mode to ensure its correct behavior.

case ParentCommand.MoveToWaitingChildren:

src/classes/child-processor.ts:161

• Introduce unit tests for the moveToWaitingChildren proxy function to validate its command forwarding functionality.

moveToWaitingChildren: async (token?: string) => {

[manast]

Not having a test for moveToDelayed was definitely an overlook from out part, we will fix it asap.

[manast]

I actually checked in the codebase and there is indeed a test for moveToDelayed, you can use it for inspiration for your moveToWaitingChildren: https://github.com/taskforcesh/bullmq/blob/master/tests/test_sandboxed_process.ts#L892