DataProbe "sensing tolerance" should respect zoom

[zepumph]

Over in #153, we want to greatly increase the maximum that zoom-out that can occur, but one of the main barriers for it from a usability standpoint is the ability for the data probe to detect the points on a trajectory. If we have the sensing logic account for the current zoom, then this problem will be accounted for, and adjusted for all zoom levels, not just the ones added over in #153.

Over here I will just work on the refactor of zoom. This will involve moving the zoomProperty over to the model so that the DataProbe's calculations can utilize it. It shouldn't be too hard, but it will change the PhET-iO instrumentation as well, making it model.zoomProperty instead of in the viewProperties.

[zepumph]

@arouinfar please review this as you review #153 in general. Please note the change of zoomProperty from the view to the model (especially for PhET-iO).

[arouinfar]

Projectile Motion is an "if-time" quarterly goal, so marking as on-hold.

[arouinfar]

Unassigning myself until work on this flavor of Projectile Motion resumes.