feat: #1070 - OCR for packaging

[monsieurtanuki]

New files:

• ocr_helper.dart: OCR Helper, to be implemented for ingredients and packaging for instance.
• ocr_ingredients_helper.dart: OCR Helper for ingredients.
• ocr_packaging_helper.dart: OCR Helper for packaging.
• tmp_ocr_packaging_result.dart: to be moved to off-dart.

Impacted files:

• app_en.arb: added 6 labels for packaging OCR.
• edit_ingredients_page.dart: refactored around new class OcrHelper.
• edit_product_page.dart: added access to edit packaging OCR; refactored.
• knowledge_panels_builder.dart: refactored.
• product_query.dart: added packaging fields to the product fields we get from the server.

What

• Implementation of packaging OCR in the same spirit as ingredients OCR.

Screenshot

Fixes bug(s)

• Closes: Reuse the mechanism for ingredients extraction for packagings #1070

[codecov-commenter]

Codecov Report

Merging #2383 (1f3a666) into develop (2ea0da3) will decrease coverage by 1.30%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           develop   #2383      +/-   ##
==========================================
- Coverage     8.86%   7.56%   -1.31%     
==========================================
  Files          161     204      +43     
  Lines         6623    9719    +3096     
==========================================
+ Hits           587     735     +148     
- Misses        6036    8984    +2948     

Impacted Files	Coverage Δ
...kages/smooth_app/lib/widgets/attribute_button.dart	0.00% <0.00%> (-92.00%)	⬇️
...s/smooth_app/lib/data_models/user_preferences.dart	8.73% <0.00%> (-23.57%)	⬇️
packages/smooth_app/lib/themes/smooth_theme.dart	60.00% <0.00%> (-22.98%)	⬇️
...p/lib/generic_lib/dialogs/smooth_alert_dialog.dart	15.29% <0.00%> (-18.92%)	⬇️
...mooth_app/lib/data_models/product_preferences.dart	24.65% <0.00%> (-6.78%)	⬇️
packages/smooth_app/lib/main.dart	14.40% <0.00%> (-3.49%)	⬇️
.../smooth_app/lib/pages/onboarding/welcome_page.dart	0.00% <0.00%> (-3.13%)	⬇️
.../smooth_app/lib/pages/onboarding/scan_example.dart	0.00% <0.00%> (-2.28%)	⬇️
...p/lib/pages/onboarding/consent_analytics_page.dart	0.00% <0.00%> (-1.57%)	⬇️
...smooth_app/lib/pages/product/new_product_page.dart	0.00% <0.00%> (-0.88%)	⬇️
... and 203 more

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[teolemon]

👌

[teolemon]

Fine factoring work @monsieurtanuki 👌

[monsieurtanuki]

Thank you @teolemon for your review! Indeed I like to code in OOP.

Not sure how it works with packaging though: on one hand the server says "Papier,Envelope" (for "Wasa Fibres"), on the other hand the OCR says something totally different. How is transformed on the server side? How relevant is it for the user to read different things in the same entry field, depending on the purpose - user-friendly or OCR codes? To be continued, probably...

[teolemon]

@monsieurtanuki The OCR-ized text is saved into the new per language field, which is parsed server side to feed the new packaging structure, which is used for Eco-Score computation.
The old structure (with commas) is leveraged when we have nothing in that field

[monsieurtanuki]

@teolemon I don't know what to do then if we have two different ways of describing packaging: old fashioned "papier,envelope" and new packaging structure. Two text input fields, with one that can be filled with the OCR result?
We'll see how users react to the current page.