allow simultaneous pinch & pan on iOS

[incanus]

We lost this with 🏃 & 🍌.

1. Put two fingers on map.
2. Pan them around.
3. Also pinch and zoom them.

The map should always stick to your fingers.

/cc @1ec5

[friedbunny]

I noticed a while back that MapKit disallows panning while pinch-zooming when location tracking is enabled, which feels kind of nice and has the benefit of not disabling tracking by accidentally panning.

If we want to copy this MapKit-like behavior, it could be good to do it in conjunction with this ticket?

[incanus]

Per chat we're gonna punt this to b2. @friedbunny We can probably ticket that one off separately on b2 as well.

[friedbunny]

As of 3.3.0b1 (and probably v3.2.x, as I seem to recall us addressing this then), the points underneath your fingers do not change while you’re interacting with the map.

[1ec5]

This got fixed in #4427.