Scheduling information for pod and podgroup may need to be modified

[sivanzcw]

For a pod, if job of the pod does not meet the schedling restriction (such as gang), it will be scheduled failed, the events of the pod likes:

Events:
  Type     Reason            Age   From     Message
  ----     ------            ----  ----     -------
  Warning  FailedScheduling  111s  volcano  10/6 tasks in gang unschedulable: job is not ready, 10 minAvailable, 6 Pending.
  Warning  FailedScheduling  104s  volcano  10/10 tasks in gang unschedulable: job is not ready, 10 Pending, 10 minAvailable.
  Warning  FailedScheduling  97s   volcano  10/16 tasks in gang unschedulable: job is not ready, 10 minAvailable, 16 Pending.
  Warning  FailedScheduling  81s   volcano  10/22 tasks in gang unschedulable: job is not ready, 10 minAvailable, 22 Pending.
  Warning  FailedScheduling  74s   volcano  10/26 tasks in gang unschedulable: job is not ready, 10 minAvailable, 26 Pending.
  Warning  FailedScheduling  66s   volcano  10/30 tasks in gang unschedulable: job is not ready, 10 minAvailable, 30 Pending.

job is not ready in the above event is ambiguous, job may be confused with the batch/v1 job in kubernetes

For podgroup, events of the podgroup during scheduling likes:

Status:
  Phase:    Running
  Running:  12
Events:
  Type     Reason         Age   From     Message
  ----     ------         ----  ----     -------
  Warning  Unschedulable  44s   volcano  0/0 tasks in gang unschedulable: job is not ready, 12 minAvailable.

the scheduler only record unschedulable events for podgroup and does not provide scheduling success information

[sivanzcw]

#520