Harden backup-utils for Cluster

[github-product-roadmap]

Summary

The preflight checks from backup-utils v.312.0 onwards will better support customers using our cluster topology. These checks will improve the performance of backup-utils by performing the following checks:

1. Verify that all remote file systems are not read-only, and highlight the nodes that are not writable.
2. Log an error message from ghe-cluster-host-check for each cluster node that is offline, so that customers know which nodes to fix before starting to generate a backup.
3. On High Availability setups, backup-utils will now write the temporary .sync_in_progress lock file (which should pause network maintenance globally) to both the primary and replica nodes during backups.