Improve trackpad navigation in 3D view with Auto Depth enabled.
{T77509}
Just store and reuse the previous data.
**Ver.1** Calculate a new depth only if the time between events is more than 250ms.
New depth picked when you stay in one place too long,
it can sometimes happen unintentionally, but overall it works great.
https://developer.blender.org/D8760?id=31075
**Ver.2** This patch allows the use of gesture phases for trackpad events, such as begun or ended.
It allows pick the depth point only once when the user begins a new gesture.
The gesture ends when you lift your fingers off.
https://developer.blender.org/D8760?id=31074
https://developer.apple.com/documentation/appkit/nsevent/1533550-phase
https://developer.apple.com/documentation/appkit/nsevent/1525439-momentumphase
https://developer.apple.com/documentation/appkit/nseventphase