LSIF: Logging and Tracing

Created by: efritz

Add logging and opentracing support.

Reviewer Notes: Relevant files include the following:

• logging.ts (sets up logger and has helper functions to log a unit of work)
• tracing.ts (sets up tracer and has helper function to trace a unit of work)
• monitoring.ts (combines the behaviors in the two files above)
• worker.ts (sets up logger, small endpoint refactor, adds log/trace middleware)
• server.ts (sets up logger, small job definition refactor, adds log/trace wrappers to jobs)

All other files simply either thread the logger/tracer instances around, or wrap exiting code with a trace or log invocation.