move interface/slice to source/RobotAPI/interface

CMakeLists.txt

interface/CMakeLists.txt

interface/slice/.gitkeep

source/RobotAPI/CMakeLists.txt

source/RobotAPI/interface/CMakeLists.txt

source/RobotAPI/interface/hardware/HardwareInterface.ice

...PI/interface/observers/KinematicUnitObserverInterface.ice

...API/interface/observers/PlatformUnitObserverInterface.ice

source/RobotAPI/interface/robotstate/LinkedPoseBase.ice

source/RobotAPI/interface/robotstate/PoseBase.ice

source/RobotAPI/interface/robotstate/RobotState.ice

...tAPI/interface/robotstate/RobotStateObserverInterface.ice

...PI/interface/selflocalisation/SelfLocalisationProcess.ice

source/RobotAPI/interface/units/ForceTorqueUnit.ice

source/RobotAPI/interface/units/HandUnitInterface.ice

source/RobotAPI/interface/units/HapticUnit.ice

source/RobotAPI/interface/units/HeadIKUnit.ice

source/RobotAPI/interface/units/KinematicUnitInterface.ice

source/RobotAPI/interface/units/PlatformUnitInterface.ice

source/RobotAPI/interface/units/TCPControlUnit.ice