Update hived request generation in rest-server

new schema in OpenPAI job protocol:

extras:
  gangAllocation: true/false
  hivedscheduler:
    jobPriorityClass: crit | prod | test (default) | oppo
    taskRoles:
     <taskrole_name>:
        pinnedCellId: string | null (default)
        # if resourcePerInstance doesn't exist, we should calculate it from 
        # config.taskroles.<taskrole_name>.resourcePerInstance, and use null as skuType
        resourcePerInstance:
          skuNum: number 
          skuType: string | null (default)
       withinOne: string | null (default)
    taskRoleGroups:
        # we don't allow single group: length of taskRoles must be > 1 
        # we don't allow overlap
      - taskRoles: [master, worker]
         withinOne: string | null

Remaining question:

• will extras.gangAllocation have any effect? - use the same behavior as before
• should we modify api/v2/cluster/sku-types - should provide a new api which returns all cell chain
• IgnoreK8sSuggestedNodes?