Support Network requestWillBeSentExtraInfo and responseReceivedExtraInfo events

[`Network.requestWillBeSentExtraInfo`](https://chromedevtools.github.io/devtools-protocol/tot/Network#event-requestWillBeSentExtraInfo)
[`Network.responseReceivedExtraInfo`](https://chromedevtools.github.io/devtools-protocol/tot/Network#event-responseReceivedExtraInfo)

Added in July. From the change (https://chromium-review.googlesource.com/c/chromium/src/+/1592771), looks like it was to include updated information about blocked cookies and for better [dealing with request information coming from outside of the renderer process](https://bugs.chromium.org/p/chromium/issues/detail?id=849483). See also e.g. previous issues like https://github.com/GoogleChrome/puppeteer/issues/487#issuecomment-324237551

One real example already is my confusion in https://github.com/GoogleChrome/lighthouse/pull/9731#issuecomment-535163364 :)

Biggest pain adapting our current setup will be the event ordering, since "there is no guarantee whether requestWillBeSent or requestWillBeSentExtraInfo will be fired first for the same request" (and same for `responseReceivedExtraInfo`)