Textual snapshot diffs were previously broken in the HTML Report. The strikethrough'd text extended beyond the intended region.
HTML Report Before:
<img width="693" alt="Screen Shot 2021-12-27 at 4 43 35 PM" src="https://user-images.githubusercontent.com/11915034/147518750-a60f9002-6eed-48a1-a412-20fabd076fa6.png">
HTML Report After:
<img width="206" alt="Screen Shot 2021-12-27 at 4 48 37 PM" src="https://user-images.githubusercontent.com/11915034/147518762-19a4c8f9-ccc3-4a3c-a962-5a42edc6fc5d.png">
This now matches what's expected and shown in the terminal (which has always been correct):
<img width="1384" alt="Screen Shot 2021-12-27 at 4 36 29 PM" src="https://user-images.githubusercontent.com/11915034/147518799-f538259e-5a45-4d6f-916c-a12ccb620c5b.png">
NB: This MR is a workaround, but not a root cause fix. It works, but I never fully got to the root cause so a bug upstream may be required. It's unclear whether it's (1) in [`colors`](https://www.npmjs.com/package/colors), (2) in [`ansi-to-html`](https://www.npmjs.com/package/ansi-to-html), or (3) Playwright's use of the two. Since the terminal output is correct, I suspect it is in `ansi-to-html`. For example:
```js
const colors = require("colors");
const Convert = require('ansi-to-html');
const convert = new Convert();
// original (strike incorrectly wraps everything in the HTML)
console.log(convert.toHtml(colors.strikethrough("crossed out") + ' ' + colors.red("red")))
// prints: <strike>crossed out <span style="color:#A00">red<span style="color:#FFF"></span></span></strike>
// workaround
console.log(convert.toHtml(colors.reset(colors.strikethrough("crossed out")) + ' ' + colors.red("red")))
// prints: <strike>crossed out</strike> <span style="color:#A00">red<span style="color:#FFF"></span></span>
```
Fixes#11116
This patch:
- rolls stable-test-runner to Nov 2, 2021 tip-of-tree
- introduces a new npm script, `npm run vtest`, to run Visual Regression
Tests for our HTML reporter
