Merge remote-tracking branch 'origin/pull/485'

Merge remote-tracking branch 'origin/pull/492'

Merge remote-tracking branch 'origin/pull/483'

fix(kernel-install): sign installed kernel, not source image

docs(kernel-install): add grub layout comment

fix(kernel-install): support grub layout

installkernel: remove bashisms

Also add files to the database that are already signed

Merge remote-tracking branch 'origin/pull/480'

clean up binary blogs

Fix parsing for EFI binaries signed by `systemd-sbsign`

Merge remote-tracking branch 'origin/pull/473'

Merge remote-tracking branch 'origin/pull/469'

Short circuit if no smartcards are found

Filter out non Yubikey smart cards