Reduce number of packages in the demo

[pahmann]

Building the cluster demo involves many packages which become part of the final image. The idea is to reduce the image size step by step towards a minimal image needed to fulfill the use case.

A comparison to the content of the medical devices working group image can make sense as well.

[pahmann]

The cluster demo packages is not fully optimized, but already stripped down. Packages needed in AGL, but maybe not in ELISA add a lot of components due to the dependency tree. (Example: Screen sharing from infotainment to cluster)
Trimming down can reduce the foot print, which matches how industrial and automotive products are build.
However, it is not crucial now and not blocking other activities on the workload analysis.