Scale up & down should support priority

[jasonyihk]

this is feature request.

scale up & down should support priority/sequence, e.g. add a flag: DOWN_PRIORITY = cronjobs,deployments, statefulsets when scale down, should scale cronjobs 1st, then deployments (most are applications), and statefulsets (most are DB, redis, queue)..

same for scale up, add a flag: UP_PRIORITY = statefulsets,deployments,cronjobs. when scale up, should scale statefulsets 1st, then deployments, and statefulsets

tks,