Support for etcd snapshot and restore about rke2 HOT 3 CLOSED

Using rke2 beta16 to validate:

• Overall the flags are working well
• Cluster backups from local work as expected
  • Note that when doing local backups, if the node(s) that were specified to contain a local backup are deleted, then those backups are also lost.
• Must install from binary instead of install script if wanting the ability to use backups: #293
• Not working in k3s for some reason: k3s-io/k3s#2201

from rke2.

• This has now been fully validated in k3s
• Going to do another round of validations in rke2, especially regarding quorum loss scenario, and then can close assuming that works as expected.
• One minor issue regarding logging opened: k3s-io/k3s#2244

from rke2.

I think the support for etcd snapshot and restore is functional. There are a few issues that came from testing this that should be addressed on their own at this point.
Namely #320 and #353

from rke2.