Bhamehta/code cleanup

[bmehta001]

Fixes runtime thread-safety, shutdown-safety, and response-lifetime issues that affect normal SDK operation. Split out from microsoft#1415 per reviewer request so runtime behavior changes stay separate from CI/build/test fixes.

Fix HTTP cancellation and callback tracking

HttpClient_Apple.mm

• Scope cancellation to the current request’s m_dataTask instead of canceling every task on the shared static NSURLSession.
• Fix the CancelAllRequests() wait loop so m_requests.empty() is checked while holding m_requestsMtx.

HttpClientManager.cpp

• Fix the cancelAllRequests() wait loop so m_httpCallbacks.empty() is checked while holding m_httpCallbacksMtx.

Fix HTTP response lifetime on abort/network-failure paths

HttpResponseDecoder.cpp

• Preserve ctx->httpResponse through requestAborted(ctx) and temporaryNetworkFailure(ctx) so downstream storage/statistics handlers can still read status and headers.
• Avoid leaking aborted/network-failure responses by keeping ownership with EventsUploadContext, whose clear() path deletes the response.

HttpResponseDecoderTests.cpp

• Add regression coverage that aborted and network-failure decode routes still receive the response object with result/status intact.

Fix WorkerThread shutdown safety

WorkerThread.cpp

• Add an explicit shutdown gate so late Queue() calls are rejected once teardown starts.
• Enqueue the shutdown sentinel only once under the queue lock.
• Clean up pending queued/timer tasks only after a successful join(), and avoid cleanup after detach() because the worker may still be running.
• Log join/detach failures instead of silently swallowing all exceptions.

Make TransmissionPolicyManager scheduling consistently mutex-guarded

TransmissionPolicyManager.cpp / .hpp

• Guard m_isUploadScheduled, m_runningLatency, and m_scheduledUploadTime consistently with m_scheduledUploadMutex.
• Avoid holding m_scheduledUploadMutex across potentially blocking cancellation during stop/shutdown.
• Keep force/zero-delay no-wait cancellation under the scheduler mutex so a competing delayed schedule cannot suppress an immediate upload.
• Use an explicit std::chrono::milliseconds value in the bandwidth-controller reschedule path.

TransmissionPolicyManagerTests.cpp

• Add regression coverage for the force/zero-delay scheduling race.

Fix Logger static-destruction-order crash

Logger.cpp

• Remove destructor logging from Logger::~Logger() because it can run after logging infrastructure has already been destroyed, causing crashes during static teardown.

Validation

• HttpResponseDecoderTests.* and TransmissionPolicyManagerTests.ForceScheduleRetainsImmediateUploadWhenCancelBlocks passed.
• Full host UnitTests passed: 485/485