Add Object Memory

• Define ARON for ObjectPose (as RobotAPI/libraries/ArmarXObjects/aron/ObjectPose.xml in a suitable namespace as a twin of armarx::objpose::ObjectPose) -> @fabian.reister
• Implement conversion from and to ObjectPose (fromAron(), toAron()) in a seperate header, e.g. aron_conversions.h -> @fabian.reister
• Refactor ObjectPoseObserver to use Memory as data structure -> @RainerKartmann

Proposed:

• ObjectPose.h: remove Ice-dependency
  • remove ice interface header
  • define ObjectTypes enum (previous: ObjectTypeEnum)
  • move ice conversions from ObjectPose.h to ice_conversions.h