Expand instrumentation for Falcon

[kaylareopelle]

After we complete #2188, it'll have instrumentation on-par with other dispatchers such as unicorn and puma.

• Investigate Falcon's features to see what unique values we should/could instrument (traces, metrics, logs, etc.)
• Implement the instrumentation, or create new tickets for the implementation

[workato-integration]

https://issues.newrelic.com/browse/NR-163370