feat: Photo gallery with tabs

[g123k]

Hi everyone!

Here's the final touch for the photo gallery.
🎥 Video: https://github.com/user-attachments/assets/8308da52-1577-492d-afe6-4d1e35f48e20

There are now tabs for languages on top of the screen:
 

And the action button is not a FAB anymore, but a footer button:

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0.89286% with 444 lines in your changes missing coverage. Please review.

Project coverage is 6.78%. Comparing base (4d9c7fc) to head (154910c).
Report is 481 commits behind head on develop.

Files with missing lines	Patch %	Lines
...oduct/gallery_view/product_image_gallery_view.dart	0.93%	106 Missing ⚠️
...oduct/gallery_view/product_image_gallery_tabs.dart	1.86%	105 Missing ⚠️
packages/smooth_app/lib/widgets/smooth_tabbar.dart	0.00%	87 Missing ⚠️
.../gallery_view/product_image_gallery_photo_row.dart	0.00%	69 Missing ⚠️
packages/smooth_app/lib/pages/image_crop_page.dart	0.00%	37 Missing ⚠️
.../lib/cards/product_cards/smooth_product_image.dart	0.00%	13 Missing ⚠️
packages/smooth_app/lib/helpers/ui_helpers.dart	0.00%	13 Missing ⚠️
...s/smooth_app/lib/helpers/border_radius_helper.dart	0.00%	8 Missing ⚠️
...app/lib/generic_lib/widgets/language_selector.dart	0.00%	4 Missing ⚠️
...pp/lib/cards/product_cards/product_title_card.dart	0.00%	1 Missing ⚠️
... and 1 more

Additional details and impacted files

@@            Coverage Diff             @@
##           develop   #5872      +/-   ##
==========================================
- Coverage     9.54%   6.78%   -2.77%     
==========================================
  Files          325     432     +107     
  Lines        16411   23843    +7432     
==========================================
+ Hits          1567    1617      +50     
- Misses       14844   22226    +7382     

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[teolemon]

• This is a very nice usability improvement for contributors
• I'd be tempted to have a secret gesture (Long press on the outdated image) or button to directly jump to the camera to refresh the current photo
• We will probably have to tweak this widget to have an inline equivalent to the tab system (drop-down, little list of available languages, accordion of available languages) when we insert it into the photos tab. By then anyway, the language shown in the photos tab will be probably good for 99% of viewers.

[g123k]

• I'd be tempted to have a secret gesture (Long press on the outdated image) or button to directly jump to the camera to refresh the current photo

For this one, I first need to change the product addition flow.
Blocked by #5857

• We will probably have to tweak this widget to have an inline equivalent to the tab system (drop-down, little list of available languages, accordion of available languages) when we insert it into the photos tab. By then anyway, the language shown in the photos tab will be probably good for 99% of viewers.

An alternative would be to show a different layout on the product page, with only the "best pictures".
However, if photos are missing, a message will be displayed.
The idea would be to keep the advanced view in editing and a simplified view on the product page.

[g123k]

@teolemon I have a doubt about my implementation.
It will always open the default language (the current issue with missing photos will disappear).

Is it what we want? Or should I open the tab containing the user language?

[teolemon]

If and only if it has photos already. Otherwise, it's just a tap away to add photos.
Let's avoid wrong incentives.

[g123k]

Ok, so I let this PR as is