Add a range of JRE versions as external dependency

It would be useful to document in each JAR, what is the minimal JRE version required by the library. This information is hard to come by, since it is not present in neither the POM nor the manifest.

Start by tracing how the Maven plugin builds its BOM entries for JARs and where POM or manifest metadata is read. The work is done when each generated JAR records its minimal required JRE version as an external dependency, with coverage for the resulting metadata.

Written by the indexing model from the issue text.