Resolve "Export extrinsic matrix in .trf in calibration activity"

What does this MR do?

Export extrinsic matrix in .trf format.

Closes #179 (closed)

• add an optional outputt in SOpenCVExtrinsic (aka ::fwData::TransformationMatrix3D)
• add new action button to call writer in calibrationActivity

How to test it?

1. Compile & Run ARCalibration
2. Do an extrinsic calibration
3. Click the "save" button

Some results

You will get an amazing .trf file with ... 16 values, enjoy 🎉

Depends

• !85 (merged)