Add converting data to human readable units

[krzmaz]

In this task add converting the raw values used by the controller to human readable units - cm and inches. Extend APIs to allow getting and setting the height using those units.

In the design consider the fact that we might read the desk offset ( difference between the actual desk height and the raw height which is a value read from the encoder on the piston) from the controller using dpg commands( see references for more details ) and calculate the human readable values using that.