Merge topic 'rendering-vr-reintroduce-virtual-RecognizeComplexGesture'

032d3b89 STYLE: Add missing lines in vtkVRRenderWindowInteractor
7ecbf4f1 ENH: Generalize VR binding definition related to complex gesture events
3ee0cf25 DOC: Update VR docstrings to consistently mention "complex gesture"
c07e0186 ENH: Generalize handling of complex gesture events in VR
38e241a3 ENH: Re-introduce support for custom logic handling VR complex gesture

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !9892