mir-kiosk should expose administrative applications in the snap

[ogra1]

when trying to run mir-kiosk on a raspberry pi with a rotated monitor attached i can not use:

"mirout rotate right"

because the app is not exposed via snapcraft.yaml (even though mirout, mirscreencast and friends are existing in $SNAP/usr/bin), please add an apps section with commonly used mir administration tools to the mir-kiosk snap so they can be used by a user through /snap/bin.

[ogra1]

specifically for the rotation bit a config option via "snap set mir-kiosk rotation=*" might also be helpful

[gerboland]

That's a good idea indeed