Continuation of support for Rose import of controlled units:

umbrello/import_rose.{h,cpp}
- At function loadFromMDL change argument "bool requireDesign" into
  "UMLPackage *parentPkg" defaulting to NULL. Pass parentPkg into call to
  petalTree2Uml.

umbrello/petaltree2uml.{h,cpp}
- In function handleControlledUnit pass parentPkg into call to
  loadFromMDL.
- At function petalTree2Uml change argument "bool requireDesign" into
  "UMLPackage *parentPkg" defaulting to NULL. If parentPkg is non NULL then
  create an UMLObject::ot_Package with root->initialArgs()[1] as name and
  parentPkg as parent.  Reassign parentPkg from the object created, and
  pass parentPkg into call to umbrellify.

CCBUG:81364