fwupd: Add support for the update action

Some future dock hardware needs the user to manually restart it after the update
has completed. This patch adds the update-action functionality and shows a
dialog box just like the existing detach-action one.
2 jobs for wip/hughsie/fwupd in 3 minutes and 2 seconds
Status Job ID Name Coverage
  Build
passed #789290
debian-stable-x86_64

00:02:54

passed #789289
fedora-x86_64

00:03:02