Instead of checking skipped tests in mocha-utils this PR
implements a custom mocha interface for better flexibility
when skipping tests. That should allow skipping tests without
running before and after hooks.
* chore: implement a test runner on top of mocha
This PR implements a test runner on top of mocha
that performs multiple mocha runs as defined in
TestSuites.json and compares the outcome of the runs
against TestExpectations.json. This allows us to
remove most of helpers from mocha-utils and be more
flexible when defining the test configurations.
* 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).
