fix: Product edition UI improvements

[g123k]

Hi everyone!

As always, after the first PRs, a few refinements for the UI edition.

Upload banner & menu

Instead of being one on top of the other, the two are mixed

Edition keyboard

On many fields, the first letter was in lowercase -> fixed

Help

I think the UI is a bit better now

Languages selector in dark mode

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 1.37615% with 215 lines in your changes missing coverage. Please review.

Project coverage is 5.92%. Comparing base (4d9c7fc) to head (84f34ff).
Report is 719 commits behind head on develop.

Files with missing lines	Patch %	Lines
...ages/product/edit_product/edit_product_footer.dart	0.65%	152 Missing ⚠️
...pp/lib/generic_lib/widgets/languages_selector.dart	0.00%	16 Missing ⚠️
...nutrition_page/widgets/nutrition_facts_editor.dart	0.00%	8 Missing ⚠️
packages/smooth_app/lib/widgets/smooth_banner.dart	0.00%	8 Missing ⚠️
...oth_app/lib/widgets/smooth_explanation_banner.dart	0.00%	7 Missing ⚠️
...p/lib/pages/product/simple_input_page_helpers.dart	0.00%	6 Missing ⚠️
...ges/smooth_app/lib/helpers/collections_helper.dart	0.00%	5 Missing ⚠️
...roduct/product_page/footer/new_product_footer.dart	0.00%	4 Missing ⚠️
packages/smooth_app/lib/resources/app_icons.dart	25.00%	3 Missing ⚠️
...generic_lib/bottom_sheets/smooth_bottom_sheet.dart	0.00%	2 Missing ⚠️
... and 4 more

Additional details and impacted files

@@            Coverage Diff             @@
##           develop   #6320      +/-   ##
==========================================
- Coverage     9.54%   5.92%   -3.63%     
==========================================
  Files          325     477     +152     
  Lines        16411   28337   +11926     
==========================================
+ Hits          1567    1678     +111     
- Misses       14844   26659   +11815     

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