* feat: use CDP's auto-attach mechanism
In this PR, we refactor Puppeteer to make use of the CDP's auto-attach mechanism. This allows the backend to pause
new targets and give Puppeteer a chance to configure them properly. This fixes the flakiness related to dealing with
OOPIFs and should fix some other issues related to the network interception and navigations. If those are not fixed completely by this PR, the PR serves a solid base for fixing them.
Closes https://github.com/puppeteer/puppeteer/issues/8507, https://github.com/puppeteer/puppeteer/issues/7990
Unlocks https://github.com/puppeteer/puppeteer/issues/3667
BREAKING CHANGE: With Chromium, Puppeteer will now attach to page/iframe targets immediately. Browser.connect requires an explicit product name when connecting to Firefox since Firefox does not support CDP's auto-attach.
* The testing tsconfig.json inherits from the base TS config.
* A lot of type assertions have been inserted...a lot.
* All testing utilities have migrated to TS.
* text-diff is being replaced with diff for TS compatibility.
* ProtocolError has been added to PuppeteerErrors and PuppeteerErrors is no longer a record (it's been frozen).
* Fixes a small bug where null was an allowable media type in emulation (should be undefined).
