Add video tutorial for deeplinks panel

[elliette]

Most panels in DevTools have a video tutorial link next to the docs link. It would be nice to link to https://www.youtube.com/watch?v=d7sZL6h1Elw in the deep links panel.

[binSaed]

I've opened a PR for this: #9925. It adds a tutorialVideoUrl field to ScreenMetaData and sets it for the Deep Links panel so the "Watch tutorial" link appears in the status line.