Only ignore nodes that are in discovering/discovered states

Nodes could be applying, readying, or even installing: we'd still want
to include these nodes by default.
Fix crash on initial apply
Add do_reboot attribute to decide if node will be rebooted or not
Make gpg_checks a required attribute
Rename javascript method
Make do_reboot select disabled when there won't be any reboot
Make it possible to reboot on later runs
Fix javascript to enable/disable do_reboot