chore(metric alerts): Zoom out alert chart for anomaly detection

[aayush-se]

• Make Dynamic Alert metric alert charts display 14 days worth of data
  • Received feedback that charts are too zoomed in so everything looked like a false postive. Upon zooming out, it was clear that there is an anomaly.

[codecov]

Codecov Report

Attention: Patch coverage is 25.00000% with 3 lines in your changes missing coverage. Please review.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/sentry/incidents/charts.py	25.00%	3 Missing ⚠️

❌ Your patch check has failed because the patch coverage (25.00%) is below the target coverage (50.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@           Coverage Diff            @@
##           master   #89940    +/-   ##
========================================
  Coverage   87.63%   87.64%            
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  Files       10244    10250     +6     
  Lines      576743   577033   +290     
  Branches    22719    22719            
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+ Hits       505425   505727   +302     
+ Misses      70875    70863    -12     
  Partials      443      443