driver tmcm: improve reference procedure

do a small move in between the fast and slow reference moves to ensure
the final move always ends up at the same place.

With this, it seems the repeatability of the reference move on the Delphi is
within a few µm (instead of up to 30µm)
Metadata update instead of stage move
Merge branch 'kimon-MiniCalibration' of delmic-server.local:odemis into kimon-MiniCalibration
Merge branch 'kimon-MiniCalibration' of vpn.delmic.com:odemis into kimon-MiniCalibration