[feature]: Create pf-backup-cluster command

[fullykubed]

Prior Search

• I have already searched this project's issues to determine if a similar request has already been made.

What new functionality would you like to see?

Create a command the creates a Velero backup of the cluster

How would you use this new functionality?

Backups should follow certain rules such as https://cert-manager.io/docs/devops-tips/backup/#velero to avoid causing issues during restores. It's unlikely most users will remember all this rules so we should create a simple command that automatically implements them.