feat(billing): Introduce Outcomes Dead Letter Queue type

[dashed]

Introduce Topic.OUTCOMES_DLQ to be used for the dead letter queue on the outcomes consumer.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.01%. Comparing base (5aeaf13) to head (a77f8ca).
Report is 11 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #73334   +/-   ##
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  Coverage   78.01%   78.01%           
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  Files        6632     6632           
  Lines      296035   296124   +89     
  Branches    50986    50999   +13     
=======================================
+ Hits       230957   231028   +71     
- Misses      58794    58811   +17     
- Partials     6284     6285    +1     

Files	Coverage Δ
src/sentry/conf/types/kafka_definition.py	100.00% <100.00%> (ø)

... and 20 files with indirect coverage changes

[lynnagara]

Lgtm, but all topics need to have their configuration defined in https://github.com/getsentry/sentry-kafka-schemas before they can be used