Converter fails on artifacts with no GAV and bundle names with special characters

When the converter finds a bundle, it will first try to "read the GAV" from potentially embedded pom.properties. If it can't, it will fallback to the symbolic name as the groupID and the bundle name as the artifactID. That is problematic as the bundle name can contain special characters like e.g. : which are not allowed in an artifactID.

Furthermore, if a bundle doesn't have pom.properties, it might still have the original pom.xml embedded (see [0] for an example).

The converter should fallback to that embedded pom first before trying to use the bundle metadata. If that fails as well, it should likely use different parts of the metadata but regardless, properly escape whatever it uses.

[0] https://repo1.maven.org/maven2/org/osgi/org.osgi.service.jdbc/1.0.0/org.osgi.service.jdbc-1.0.0.jar