Add "record my clicks before running tests" feature

[beaufortfrancois]

Some websites require some user interaction to be able to unveil some new UI (such as clicking on a "play" button to play a video) and it would be great if Lighthouse support some kind of "start record / stop record" button that record all user interactions before running some audits / tests.

cc @samdutton

[ebidel]

Related:

• "Live mode" pause on violation - Live mode: Pause on violation #735
• Make page refresh optional, depending on config #1769 - potentially not reloading the page. Get it in a state, and audit.

[paulirish]

Related:

• testing entire login route Testing the entire login route through Lighthouse #2058
• Question: How to test page behind authentication? Question: How to test page behind authentication? #1418

[paulirish]

duping into #1418