Checks for queue item

[XiongKezhi]

Will add the implementation in the GitHub Checks plugin later.

[XiongKezhi]

I'll later push some changes on master to suppress "hidden field" checkstyle warning and merge it here to pass the CI.

[timja]

I would like to see the github side of this as I don't really understand what this is for.
Or at least some more description

[XiongKezhi]

Sorry, I should add the context.

Before this, when we publish the "queued" checks for the main build, we extend the RunListener and override the onInitialize method, but it looks like that onInitialize is triggered after the job leaves the queue and when initializing the run. Therefore, to let the "queued" checks be published when a job actually enters the queue, we have to extend another listener which is QueueListener and override the onEntersQueue method.

I added the method fromItem because I found that the Item for queue is not compatible with Run.

@timja

[timja]

lgtm once checkstyle is sorted