Add visualize operator and remove runtime.visualize.

Authored by featherless on Mon, Apr 17, 1:12 PM.

Description

Add visualize operator and remove runtime.visualize.

Summary:
The new operator can be used anywhere like so:

swift
runtime.add(tossable, to: view) { $0.visualize(in: runtime.visualizationView) }

Reviewers: O2 Material Motion, O4 Material Apple platform reviewers, Material Motion, markwei

Reviewed By: O2 Material Motion, O4 Material Apple platform reviewers, Material Motion, markwei

Subscribers: markwei

Tags: Material Motion

Differential Revision: http://codereview.cc/D3047