Validate cluster sub command

[nirs]

A DR environment have one or more hubs, and 2 managed clusters. Each cluster type have many components that has to be installed and configured in the right way to make it possible to preform DR flows successfully.

Partial list of possible issues:

• drpolicy: missing drclusters
• ramen config: missing or misconfigured
• mirrorpeer: missing or misconfigured
• secrets: missing on the hub or managed clusters
• s3 store: down, failing, not accessible
• vrc: missing
• submariner: connectivity issue, globalnet
• storage: full, broken
• rbd mirror: down, broken
• network: cluster is not accessible

The ramenctl tool should inspect all clusters and validate that the all the clusters are correct. The tool should create a report listing all the issues in the clusters, that can be attached easily to a bug tracker.