HTML API: Add test suite from html5lib #1439

Job	Run time
Core running from build / Core running from build / Linux	2m 1s
Core running from src / Core running from src / Linux	1m 59s
Core running from build / Core running from build / Windows	3m 46s
Core running from src / Core running from src / Windows	2m 57s
Core running from build / Core running from build / MacOS	4m 7s
Core running from src / Core running from src / MacOS	4m 49s
Gutenberg running from build / Gutenberg running from build / Linux	8m 41s
Gutenberg running from src / Gutenberg running from src / Linux	8m 12s
Gutenberg running from build / Gutenberg running from build / Windows	11m 38s
Gutenberg running from src / Gutenberg running from src / Windows	11m 35s
Gutenberg running from build / Gutenberg running from build / MacOS	15m 40s
Gutenberg running from src / Gutenberg running from src / MacOS	13m 42s
Leave WordPress Playground details	2s
Slack Notifications	0s
Failed workflow tasks	0s
	1h 29m 9s

Provide feedback