Inspired by: https://github.com/pi-hole/pi-hole/pull/2112
A pre-start and a post-stop script are added to reduce doubled setup and cleanup code.
Since systemd services do not natively support dynamic users, test once whether capabilities are supported during install/update, and remove User=pihole otherwise.
Signed-off-by: MichaIng <micha@dietpi.com>
Co-authored-by: DL6ER <dl6er@dl6er.de>
