Tidy up PriorityClass Handling logic in all internal helm charts

[t83714]

Tidy up PriorityClass Handling in all internal helm charts

Magda currently create priorityClass from "magda-10" to "magda-0" to control the pod schedule priority, when global.enablePriorityClass turns on.

The "magda-10" (only allocated to gateway at the moment) has highest priority and "magda-0" is the lowest one.

We want to achieve the followings:

• Turn on PriorityClass by default
• Auto check if the priority class already created (e.g. by another Magda deployment) and only create priority class when the priority class not exist
• Only update priority class value when the priority class is belong to current deployment and value is different
• When value is different but can't update (e.g. it belongs to other deployment), an error should be thrown to interrupt the deployment.
• Set "helm.sh/resource-policy": "keep" so priority class will not be removed when delete the deployment