Auto merge of #11098 - fitzgen:update-trace-dump, r=jdm

Update `trace-dump.{js,css}` from upstream

Part of making the trace-dump.js code unit testable was moving it out to another
repo. This brings in all the changes made while writing unit tests, and making
the code more unit testable.

Unfortunately, there are a lot of whitespace changes; here is the diff ignoring whitespace: https://pastebin.mozilla.org/8870346

Fixes #10905.

r? @jdm

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/11098)
<!-- Reviewable:end -->

components/profile/trace-dump.css

@@ -1,3 +1,7 @@
+/*
+!!! THIS FILE IS COPIED FROM https://github.com/fitzgen/servo-trace-dump !!!
+Make sure to upstream changes, or they will get lost!
+*/
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */