HDDS-5104. Prioritising SCM's in SCM HA setup

[sadanand48]

What changes were proposed in this pull request?

When an SCM is ready and tries to exit safemode, update the peer priority for that SCM in the Raft Ring. This will create an updateRaftPeerRequest and submit request to Ratis. Thereafter, if all SCM's are updated (with same raft log index) then preference for leadership will be given to the one with higher priority i.e to the one out of safe mode . This will make sure that SCM that is in safe mode will not be elected as leader.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-5104

How was this patch tested?

Unit tests