update orbit p2 url to newest S-release

Change-Id: Ieb3ce59884049b07d8800947fdb36b26a10a1fdc
Bug 402301: Migration: UI Independent tests

* add fragment: org.eclipse.scout.rt.testing.shared.test
* some corrections from review

https://bugs.eclipse.org/bugs/show_bug.cgi?id=402301

Change-Id: Id2ed6ff954884e20a1e13ac27c8822eb2ea6c321