Push extension+sidecar logs as Semaphore artifacts for Mocha test failures

[shouples]

We recently had an error / test stall during one of the scheduled CCloud auth smoketests, but the existing logging wasn't helpful:

And the existing artifacts in /test-results have next to no helpful information:

Since Mocha tests run in a single VS Code instance/window and share logs, we should be able to artifact push the extension logs and (formatted) sidecar logs as semaphore artifacts.