Tweak icon parsing once more to handle adjusted name format

[NicoHinderling]

This change is in tandem with this sentry-cli PR. It does three main things:

1. Reverts the changes from yesterday's multiset icon parsing launchpad PR
2. Ensures that any alternative icons won't be considered for the image optimization insight as well (they now share the same method)
3. Tweaks the file name parsing when performing the _is_alternate_icon_file and _is_optimizable_image_file checks. A change in the CLI PR causes the file_info.path to now be:

Assets.car/AppIcon_Alt_Color_Red/red-light-min.png

where before it was Assets.car/AppIcon_Alt_Color_Red. So the name matching logic had to be slightly tweaked

[codecov]

Codecov Report

❌ Patch coverage is 76.00000% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.48%. Comparing base (ceb7bed) to head (a1aec9f).
⚠️ Report is 6 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...aunchpad/size/insights/apple/image_optimization.py	66.66%	3 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #442      +/-   ##
==========================================
- Coverage   80.65%   80.48%   -0.17%     
==========================================
  Files         159      161       +2     
  Lines       13224    13392     +168     
  Branches     1381     1409      +28     
==========================================
+ Hits        10666    10779     +113     
- Misses       2038     2081      +43     
- Partials      520      532      +12     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.