automation: Consider adding WebDriver BiDi actions in addition to the WebDriver Classic endpoints

[rakuco]

As discussed in #284 (comment):

defining it [the API] as a WebDriver BiDi module would allow adding events later (if needed) and it would allow WebDriver BiDi-only clients such as Puppeteer to expose the functionality for developers to write tests for their apps.

We do not need BiDi's bidirectional capabilities at the moment, but I don't think it would hurt to define a BiDi module in the future, just like the Permissions API does.