Move get_axis_position_mm to Planner (#10718)

Marlin/src/core/utility.cpp

Marlin/src/feature/I2CPositionEncoder.cpp

Marlin/src/feature/bedlevel/ubl/ubl_motion.cpp

Marlin/src/gcode/host/M114.cpp

Marlin/src/module/motion.cpp

Marlin/src/module/planner.cpp

Marlin/src/module/planner.h

Marlin/src/module/scara.cpp

Marlin/src/module/stepper.cpp

Marlin/src/module/stepper.h

Marlin/src/module/temperature.cpp

Marlin/src/module/temperature.h