Fail early when the reachability metadata schema in the metadata repo doesn't match GraalVM

The native build tools should dispatch to the metadata release in the following way:
1. GraalVM distribution has the `reachability-metadata-schema.json` lower than the repo => exit and warn about updating
2. GraalVM distribution has no `reachability-metadata-schema.json` => use version the maximal `0.3.x` version and warn