♻️ ref(metric alerts): refactor get_metric_issue_aggregates

[iamrajjoshi]

continuing refactors for aci metric alerts, this time get_metric_issue_aggregates

[codecov]

Codecov Report

Attention: Patch coverage is 91.30435% with 6 lines in your changes missing coverage. Please review.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...egrations/discord/message_builder/metric_alerts.py	80.00%	1 Missing ⚠️
...ations/msteams/card_builder/incident_attachment.py	80.00%	1 Missing ⚠️
src/sentry/integrations/opsgenie/utils.py	75.00%	1 Missing ⚠️
src/sentry/integrations/pagerduty/utils.py	75.00%	1 Missing ⚠️
...ry/integrations/slack/message_builder/incidents.py	80.00%	1 Missing ⚠️
src/sentry/rules/actions/notify_event_service.py	80.00%	1 Missing ⚠️

Additional details and impacted files

@@                        Coverage Diff                         @@
##           raj/aci/refactor-incident-logic-2   #86266   +/-   ##
==================================================================
  Coverage                              87.88%   87.88%           
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  Files                                   9708     9708           
  Lines                                 550435   550488   +53     
  Branches                               21433    21433           
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+ Hits                                  483769   483822   +53     
  Misses                                 66287    66287           
  Partials                                 379      379