Definitions and VF changes

I combined the last 2 PRs, https://github.com/valueflows/vf-graphql/pull/47 and https://github.com/valueflows/vf-graphql/pull/48, which I will close after doing this one. Fixed all merge conflicts, so this should merge more easily. But still needs a good review @pospi and probably a compile check.

I'm going to use this one to create json-schema definitions, will come back here with anything I find that needs fixing from that exercise.