Comprehensive Logging and Metrics (Opt in)

[tznind]

I have taken this on as part of #3837

'Opt in' means you have to specifically create a logger in your host program before logging output gets created (i.e. we default to null logger).

Is your feature request related to a problem? Please describe.

• Log when key events happen e.g. Init/Shutdown
• Log fatal events in background threads e.g. input loop thread
• Knowing how long things like the iteration loop is taking

Describe the solution you'd like
Add logging abstraction dependency (i.e. ILogger).
Add standard metrics dependency e.g. System.Diagnostics.Metrics

Describe alternatives you've considered
We could roll our own or write a scenario in UICatalog but its better to just go with the standard. It also makes things work for downstream customers.