trackpad zooming too slow

### Your idea

Hi,

I could not find an issue describing this already, feel free to close and mention if there is one.
related to #4212 and #4243 pretty much describes a possible solution already.

Zooming takes way too long using my Apple Magic Trackpad, [this post](https://social.nerdzoom.media/@marius/112118255949862676) contains some GIFs that hopefully explain this issue.

> - I doubt too many people will object (or even notice) a slightly less responsive setting for zoom.
> - If I'm wrong, we can create a setting for it
@Tantacrul [in 4243](https://github.com/audacity/audacity/pull/4243#issuecomment-1408818579)

I've noticed it and I'd love a setting for this so that I can update to the newer releases, I'm stuck on v2.3.3 atm :)

### Problem to be solved

zooming on MacBooks/trackpads would be more efficient and not as slow

### Prior art

_No response_

### Additional context

_No response_

Start by reading related issues #4212 and #4243 and the linked discussion, then trace the existing trackpad zoom handling in Audacity. Done means zooming on MacBooks and Apple Magic Trackpads is faster, with the requested setting available if that is the agreed solution.

Written by the indexing model from the issue text.