Add proxy audit log and other assorted fixes

[scbedd]

This PR

• Fixes an identified issue with not properly utilizing the session locks -- causing a serious perf degradation when adding a bunch of sanitizers to a bunch of tests. (like 10+ minutes per massive core job bad)
• Fixes a serious problem that was allowing a test to be stopped while the last entry in the recording is still writing it's body. That location in the code has already obtained a lock on the session, so merely adding the same to playback/stop prevents the test from being stopped while the last entry is being streamed back. This was the source of the Channel Response timeout issues that java- core was seeing @alzimmermsft (at least, it has not reproed in the 3 core runs since I added this fix 🤞 )
• Add a concurrent queue for log messages that can be dumped. Currently this endlessly grows, but pulling with /Audit/GetAuditLogs will clean up that memory.
• Add audit entries for Record code paths
• Add a few tests for the new functionality
• Get signoff from @mikeharder about the always-on per-session audit logging. We were kinda laughing about chewing up memory, but...it's not that bad :P No affect to java - core which beats the absolute hell out of the server.

@mikeharder I need to add audit items to the record pathway, but I was laser focused on getting playback concurrency issues resolved for the java folks. Please take a look, see how I'm retaining the various locks on resources (by reducing to a single access lock to each playback session). I think I've nailed most of the edge cases.

@alzimmermsft looking at the latest java - core failures running with this version of the test-proxy, I don't think the proxy is related to those. I'm not declaring total victory with this PR but the issues are seriously reduced.

This version is standing up to multiple storage runs: