Queue Limits By Priority

[d80tb7]

Implements queue limits by priority. This enables lower (preemptible) pirotiy classes to be given higher queue limits in order to incentivize preemption.

Preemption configuration is now of the form:

PreemptionConfig:
PriorityClasses:
  armada-default:
    priority: 30000
    maximalResourceFractionPerQueue:
      cpu: 20
      memory: 20  
  armada-preemptible:
    priority: 20000
    maximalResourceFractionPerQueue:
      cpu: 90
      memory: 90  

As part of this PR I removed the preemption logic from the old scheduler.

[d80tb7]

I changed this because it was causing a circular reference. Essentially other armada module imported by the configuration package is problematic because configuration is imported everywhere. In this case all we were using this for was a type alias so it shouldn't really matter.

[d80tb7]

this is the old scheduler where I have removed the preemption logic

[d80tb7]

This is the old scheduler where I have removed preemption;

[d80tb7]

I've renamed this function because it claimed to validate all the armada config but all it actually did was check that the cancelJobsBatchSize was greater than 0! Clealry we need to have a better strategy for validating our configuration but that's a job for another day.