Implementing job cancellation and preemption on queue (#271)

[MustafaI]

• Implementing job cancellation/preemption by queue

• Adding aliases for queue preempt and cancel

• Improving error messages, fixing type

• Adding cmd tests

Summary of changes:

• Adding rpcs on queue service to cancel and preempt jobs by queue name
  • Jobs can be cancelled by queue, job state and priority class
  • Jobs can be preempted by queue and priority class
• Exposing functionality in Armadactl
  • Allows for selecting by label
  • Adding tests