fix/#90 - matching the coding rules in order to get a better pub.dev score

[monsieurtanuki]

Impacted files:

• analysis_options.yaml: added a reference to pedantic, with limits
• pubspec.yaml: added a reference to pedantic: ^1.9.2 for code analysis
• tons of dart files: minor fixes in order to match the coding rules

[MohamedFBoussaid]

@monsieurtanuki Thanks, this will improve the score.
I saw that the flutter analyser on Github actions here : https://github.com/monsieurtanuki/openfoodfacts-dart/runs/1881588895?check_suite_focus=true , other things that can be improved :
info • Unnecessary new keyword • example/lib/main.dart:134:11 • unnecessary_new
info • Unnecessary new keyword • lib/utils/HttpHelper.dart:65:27 • unnecessary_new

[monsieurtanuki]

@MohamedFBoussaid Sorry about that, I've just fixed both lines.

Actually as far as I understand that may not improve the score for the moment, as stated in #90 (about SearchResult.dart). But there's a bit of confusion about which criteria are used in the pub.dev score.

[MohamedFBoussaid]

@monsieurtanuki thanks, yeah the analyzer is a bit confusing on pub.dev