feat: statsd configuration through environment variables

[aldy505]

Because of getsentry/sentry#102988, we want to start telling people to use statsd to monitor their self-hosted sentry. This is another part of it.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.49%. Comparing base (275e7d0) to head (5a039cd).
⚠️ Report is 1 commits behind head on master.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4031   +/-   ##
=======================================
  Coverage   99.49%   99.49%           
=======================================
  Files           3        3           
  Lines         197      197           
=======================================
  Hits          196      196           
  Misses          1        1           

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