Rudder

As seen in #12447, #12448 and other, we need to be able to easely update required permission for the JS sandbox because they change massively between each (minof) jvm release.

For that, we need to defined our "java.policy" file and use it - but only for the javascript vm. There is hint about how to do that here: https://docs.oracle.com/javase/8/docs/technotes/guides/security/permissions.html and more particulary https://docs.oracle.com/javase/8/docs/technotes/guides/security/PolicyFiles.html#DefaultLocs

But it seems that just setting "java.security.policy=someURL SomeApp" system property will affect all Rudder, which is not what we want.

Need some tests.