* Revert "feat: 3585 - upgrade to flutter 3.7 (#3666)"
This reverts commit ad46236bdf77afea18b12cc69b3ee64a6752ee73.
* fix: 3723 - now always replaces decimal separator for number format
Impacted files:
* `strings_helper.dart`: removed now useless methods
* `text_input_formatters_helper.dart`: now works in all cases, regardless of the presence of group separator in the target language, given that we don't use group separators in our decimal number formats anyway
* fix: 3723 - unrelated localization fix
Impacted file:
* `app_ar.arb`
* Nutritional values: ensure only one decimal separator is displayed
* Add an assert
* Some tests for StringExtensions
* More tests
* Better support multiple separators