[License] Clean the code from the plugin org.eclipse.papyrus.dev.project.management

When I initialized the git with the Papyrus code, I get this error during the first run of the build.

I already update the licence for infra.guava, but we shouild remove the old code from org.eclipse.papyrus.dev.project.management:

• remove the handlers to add the EPL1, the about.html and the licence.html file.
• Maybe other code should be deleted too.