Dropping Snap.svg dependency

[kimikage]

ProfileSVG does not fully utilize the functions of Snap.svg. Now that the SVG support on major browsers is "somewhat" stable, I don't think we need to use Snap.svg.

Originally posted by @kimikage in #9 (comment)

In fact, Snap.svg is useful, but it also causes poor performance. In particular, regarding memory leaks (#19), it complicates the problem.

[fonsp]

It looks like the last work on snap.svg was 5 years ago: https://github.com/adobe-webplatform/Snap.svg/commits/master

A good alternative might be d3, which has zoom-and-pan built in!
https://observablehq.com/@d3/zoom