Improve jar naming

[jzy3d]

A couple of suggestions for the artifact names :

• Add separators in the names to make them more readable
• Do not name them with "jar" (they are jars)
• Use the embedded VTK version number (9.1) Why not using 9.1-rc2 for your next one if you want to indicate different versions relative to the same VTK version.

Which would lead to

• vtk-java-natives-9.1-rc2.jar
• vtk-java-natives-vtk-9.1-rc2.jar
• vtk-java-natives-gluegen-2.4-rc4-rc2.jar
• vtk-java-natives-jogl-2.4-rc4-rc2.jar