refactor(logging): Clean up `statsd` logging

[sebastianliebscher]

SUMMARY

This PR removes the log_to_statsd= functionality from the @event_logger and replaces usage with already existing @statsd_metrics decorator. I basically moved BaseSupersetApiMixin from base_api.py --> base.py so that the flask views can use @statsd_metrics too.

Currently, there are two decorators for basically the same use case:

• @event_logger.log_this_with_context(log_to_statsd=True)
• @statsd_metrics

The @event_logger just increments a statsd counter, while @statsd_metrics additionally measures the execution time of a function.

TESTING INSTRUCTIONS

• run unit + integration tests
• manually checked for new statsd metrics

ADDITIONAL INFORMATION

• [ ] Has associated issue:
• [ ] Required feature flags:
• [ ] Changes UI
• [ ] Includes DB Migration (follow approval process in SIP-59)
  • [ ] Migration is atomic, supports rollback & is backwards-compatible
  • [ ] Confirm DB migration upgrade and downgrade tested
  • [ ] Runtime estimates and downtime expectations provided
• [ ] Introduces new feature or API
• [ ] Removes existing feature or API