When present, the aperture indicates the area of the sample's buffers to display. The frame size instead includes some undesired padding. This is the case when color planes are aligned, such as with YUV output from a decoder MFT.
-- v2: evr/mixer: Respect input media type MF_MT_GEOMETRIC_APERTURE. evr/tests: Add more video mixer input media type aperture tests. evr/tests: Split check_presenter_output to a separate helper. evr/tests: Split create_d3d_sample to a separate helper. mf/tests: Check that pan scan and geometric apertures are set.