Generate JSON schemas

[mnonnenmacher]

The JSON schemas for ORT configuration files (https://github.com/oss-review-toolkit/ort/tree/main/integrations/schemas) are currently maintained by hand. This makes it easy to forget updating them when changing the configuration model.

Automating the schema generation would ensure that they are kept up-to-date and reduce manual effort.

This library can generate JSON schemas for Kotlin classes and supports Jackson:
https://github.com/SMILEY4/schema-kenerator

[sschuberth]

I totally forgot that I already have a script for this. Mind giving that a try, @heliocastro?