IWearFrameVisualizerModule is not applying the displacement offset

if the `IWearFrameVisualizerModule` is launched with some desired displacement offset, such as
[iWearFrameVisualizerExample.txt](https://github.com/robotology/wearables/files/8095968/iWearFrameVisualizerExample.txt), all the frames seems to be visualized in the origin.

It seems in fact that the transformation that is read from the configuration file in [here](https://github.com/robotology/wearables/blob/18c2ddb2b1515429d15f82739479710d6c7a24a2/modules/IWearFrameVisualizer/src/main.cpp#L263-L294), is never used, but rather overwritten [here](https://github.com/robotology/wearables/blob/18c2ddb2b1515429d15f82739479710d6c7a24a2/modules/IWearFrameVisualizer/src/main.cpp#L341) by the measurement

cc @RiccardoGrieco @kouroshD