Enable crash dumps for uwp/wasdk unit tests

[Arlodotexe]

This PR updates our CI to emit crash dumps and diagnostic logs, which should be uploaded as artifacts.

Needed to diagnose #347

See also https://github.com/microsoft/vstest/blob/main/docs/troubleshooting.md

[Arlodotexe]

Looks like cancelling and re-running all jobs isn't re-running the successful ones. Closing and re-opening to fix.

[Arlodotexe]

Ran a few times, and even when failing during various tests, the dump seems to capture an "invalid pointer read" in the dispatcher queue extensions:

It's not immediately obvious why this is happening. I wonder if it's only happening for tests generated with UIThreadTestMethod? Maybe that's related.

[Arlodotexe]

Strange, it's not outputting crash dumps anymore 🤔

I'm seeing this:

Terminating app with process ID '7764'.
Data collector 'Blame' message: All tests finished running, Sequence file will not be generated.

Will continue to retry, it's not clear why the tests all finish but fail anyway.

[Arlodotexe]

It took five reruns, but I got the crash dump for the test failures in WASDK again :D

Since it's too large to upload inline on GitHub, to preserve the artifact I've made it available here.
_{Anyone can help preserve this artifact by downloading it using their own ipfs node, otherwise I'll keep it online as long as possible using my own devices.}

[Arlodotexe]

Digging into the crash dump, we see the throw occurring inside of DispatcherQueueExtensions.EnqueueAsync with the same stack trace as before:

Notably, looking at the stack trace across both crash dumps we've had, it's being consistent about the test failing during DispatcherQueueHelper_Action_Null at this line:

        var task = DispatcherQueue.GetForCurrentThread().EnqueueAsync(default(Action)!);