Trackpad: fix Zoom Axis restrictions for 3DView zoom.
Here was the initial code that only supports `MOUSEZOOM`, then an improvement for Vertical zoom mode only,
then an improvement for Vertical zoom mode only,
and then `MOUSEPAN` support was added but this code
was not adapt for `MOUSEPAN`.
For "Dolly", `MOUSEPAN` support was completely missed.
Currently, zoom speed depends on the Zoom Axis and
the Vertical works in both directions. This patch will fix this.
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At this point `16ca65e4a91b` all (Trackpad, Mouse, Scroll Wheel) was consistent,
zooming in - move mouse/fingers towards screen.
Later, as I see it, Apple changed the default setting to "Natural",
and now the trackpad zoom is reversed...