Add options to install bullseye in all places where buster is used, use
it as default when possible, and keep these for the moment.
Switch to bullseye in Dockerfile.
Change-Id: I2f693982ba92a671a6f2254c5a245a1d05231404
Use a single (prev CE like) approach
GRML -> main.sh -> deployment.sh -> ngcp-installer
All SP versions can be installed from a single image
Remove network configuration points from GRML installer
Change-Id: I9a56c12ca3f42d055303e5a0b08691de3560fe2c