d3d12screencapturesrc: Performance improvement
Process captured frame using d3d11 instead of d3d12, and use shared fence when copying processed d3d11 texture to d3d12 resource. In this way, capture CPU thread does not need to wait for fence signal.
Process captured frame using d3d11 instead of d3d12, and use shared fence when copying processed d3d11 texture to d3d12 resource. In this way, capture CPU thread does not need to wait for fence signal.