Add a logging extension

[Turnerj]

Add a basic logging extension that makes it easier to see the inner workings of the caching system to help debug issues.

In may prove useful to think about how this works and implementing something similar: https://docs.microsoft.com/en-us/aspnet/core/fundamentals/logging/loggermessage?view=aspnetcore-5.0

[Turnerj]

Just found out about using source generators to make efficient log messages: https://andrewlock.net/exploring-dotnet-6-part-8-improving-logging-performance-with-source-generators/

If I can do that with the .NET 6 SDK but still target older frameworks, I think it might be the way forward for landing advanced logging to Cache Tower.

[Turnerj]

Either in addition to this or alternatively to it, having support for EventSource/EventListener could be useful.