windows: replace gdigrab with dxgigrab ffmpeg device

Gdigrab window sharing is limited to the applications that
do not depend on accelerated rendering. If one tries to share
a window such as Google Chrome or VisualStudio Code with this
ffmpeg device, all that is received are black frames. The Dxgigrab
device uses the D3D11 Windows API which enables the correct
sharing of the mentioned applications and other ones.

GitLab: jami-project#1294
GitLab: jami-client-qt#481

Change-Id: I5509ed1b8d47a86367869e52127b17f671c61f77