Add classifier to maven graph

[asafambar]

• The pull request is targeting the dev branch.
• The code has been validated to compile successfully by running go vet ./....
• The code has been formatted properly using go fmt ./....
• All static analysis checks passed.
• All tests have passed. If this feature is not already covered by the tests, new tests have been added.
• All changes are detailed at the description. if not already covered at JFrog Documentation, new documentation have been added.

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[attiasas]

Please add dependnecy with a Classifier to the maven-example-with-many-types project so we can have a test with this attribute here