Ability to take Offline Snapshot when the Author-Standby has been promoted to Primary.

[michaeldiender-shinesolutions]

currently the offline snapshot will not run when the author-standby has been promoted:

it will be identified as not healthy.

https://github.com/shinesolutions/aem-stack-manager/blob/master/src/main/java/com/shinesolutions/aemstackmanager/handler/OfflineSnapshotTaskHandler.java#L58

scenarios: taking offline snapshots after promote author event. when old primary still responding and when it is not responding. currently the stack manger will not run the job. (consider changing component to author-demoted and adjust offline snapshot flow to handle the situation where there are no author-standby, or only 1 author-primary or 1 author-primary and 1 author-demoted)