LPS-33178 Adding MDRTestUtil
LPS-33178 Making liveGroup and stagedGroup protected
LPS-33178 Adding MDR related staged model data handler tests
LPS-33178 Moving Bookmarks related staged model data handler tests to proper package
LPS-33178 Julio had asked me to rename the vars back to the longer dependentStagedModels var since he said that was more clear (if I make a change you disagree with, just send me a pull changing it back, or email me… it's back and forth until we both agree, thx)
LPS-33178  Reuse existing ServiceTestUtil#getServiceContext (it does the job), and also add new methods so we can "reuse" *RandomNameMap and *RandomDescriptionMap, please apply to other tests. Thx.