fix: Store locator: Fav icon not being updated immediately

[g123k]

Hi everyone!

Demo: https://github.com/user-attachments/assets/67c0e918-47eb-477b-b12a-f15b2e8ddcbc

There are also some optimizations in the code.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 6.66667% with 14 lines in your changes missing coverage. Please review.

Project coverage is 6.36%. Comparing base (4d9c7fc) to head (414482b).
Report is 622 commits behind head on develop.

Files with missing lines	Patch %	Lines
...ages/locations/search_location_preloaded_item.dart	0.00%	8 Missing ⚠️
...h_app/lib/pages/locations/location_query_page.dart	0.00%	5 Missing ⚠️
.../lib/pages/locations/favorite_location_helper.dart	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           develop   #6158      +/-   ##
==========================================
- Coverage     9.54%   6.36%   -3.18%     
==========================================
  Files          325     449     +124     
  Lines        16411   25700    +9289     
==========================================
+ Hits          1567    1637      +70     
- Misses       14844   24063    +9219     

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