Use `transitivedependency` enricher for transitive extraction for Maven pom.xml

[cuixq]

We should be able to use the enricher added in google/osv-scalibr#1573 and deprecate pomxmlenhanceable extractor.

[G-Rath]

@cuixq should I pick this up, or are you working on it?

[cuixq]

@G-Rath I was actually leaving a comment to ask if you have time to help with this - so go for it!