[RFE] Add option --apply to bootc rollback subcommand

[Tronde]

User Story:

As a system administrator, when I need to rollback my image mode host to current rollback image, I would like to use the option --apply to reboot the the host automatically.

Current behavior:

• Currently I need to restart the host manually as there is no option to reboot automatically after issuing the bootc rollback command

$ sudo bootc rollback
Next boot: rollback deployment
$ sudo reboot NOW

Desired behavior:

$ sudo bootc rollback --apply
Next boot: rollback deployment
…

Host reboots automatically.

Additional info:

• I would like to have the option --apply as it's the same option already used for bootc upgrade and bootc switch