Add fuse-apicurito-generator image to OSBS

The fuse-apicurito-generator maven build also produces a docker image. This needs to be separated out into a dist-git repository so it can be built in OSBS. The upstream image is built using fabric8-maven-plugin, so it's likely that a simple Dockerfile is required to contain the generated jar.

The upstream repository is at:
https://github.com/jboss-fuse/fuse-apicurito-generator

NB: Image names need to be finalised and container request forms submitted to RCM.