feat: add bazzite-rollback-helper util

[aarron-lee]

This is a basic helper script to make it easier to manage rollbacks on bazzite.

====== Bazzite Rollback Helper Util ======

This Tool aims to help with rollbacks and rebases

Usage: bazzite-rollback-helper [OPTION] [ARGUMENT]

Options:
  list      List available Bazzite images, Default is "stable"
  rollback  Rolls back to previously installed Bazzite image. alias for "rpm-ostree rollback"
  current   Show currently active Bazzite image
  rebase    Rebase/rollback to specified Bazzite image, Default is bazzite-deck:stable

Examples:
  bazzite-rollback-helper list stable
  bazzite-rollback-helper rollback
  bazzite-rollback-helper current
  bazzite-rollback-helper rebase bazzite-deck:39-20240315
  bazzite-rollback-helper rebase bazzite-deck:stable
  bazzite-rollback-helper rebase stable

For more help, visit https://discord.bazzite.gg

This is based on the documentation from the bazzite discourse, as well as the util script I originally wrote here