feat(crons): Add stub consumers for clock tick / tasks

[evanpurkhiser]

We will use these to process clock ticks and their associated tasks

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 79.84%. Comparing base (aed6fb4) to head (8b73213).
Report is 1 commits behind head on master.

❗ Current head 8b73213 differs from pull request most recent head 6444c3e. Consider uploading reports for the commit 6444c3e to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #69809      +/-   ##
==========================================
+ Coverage   76.95%   79.84%   +2.89%     
==========================================
  Files        6487     6488       +1     
  Lines      288480   288308     -172     
  Branches    49684    49667      -17     
==========================================
+ Hits       221988   230198    +8210     
+ Misses      65950    57708    -8242     
+ Partials      542      402     -140     

Files	Coverage Δ
src/sentry/conf/server.py	89.18% <ø> (ø)
src/sentry/conf/types/kafka_definition.py	100.00% <100.00%> (ø)
src/sentry/consumers/__init__.py	83.33% <ø> (ø)
.../sentry/monitors/consumers/clock_tasks_consumer.py	84.61% <84.61%> (ø)
...c/sentry/monitors/consumers/clock_tick_consumer.py	84.61% <84.61%> (ø)

... and 536 files with indirect coverage changes