FORGE-1863: Create a GenerateHashcodeEquals command inside the dev-tools...

...-java addon.

After the command, it writes Success and works correctly (tested in the command line and the tests), however in the command line it also leaves an exception:
``` Exception when parsing/running: java-generate-equals-and-hashcode --targetClass org.First.First --fields myFirstField , org.jboss.forge.roaster.model.impl.JavaClassImpl cannot be cast to org.jboss.forge.addon.resource.Resource ```
The same happens for the command *java-generate-getters-and-setters*.

I copied these test methods from some parser-java commands. Should I fix them too?