fix: 3723 - now always replaces decimal separator for number format (#3734)

* Revert "feat: 3585 - upgrade to flutter 3.7 (#3666)"

This reverts commit ad46236.

* 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`

Author: monsieurtanuki

packages/smooth_app/lib/helpers/strings_helper.dart

@@ -24,10 +24,6 @@ extension StringExtensions on String {
     return positions;
   }
 
-  bool get isASpaceCharacter => this == ' ' || isANarrowBreakSpaceCharacter;
-
-  bool get isANarrowBreakSpaceCharacter => this == ' ';
-
   /// Removes a character by giving its position
   String removeCharacterAt(int position) {
     assert(position >= 0 && position < length);

packages/smooth_app/lib/helpers/text_input_formatters_helper.dart

@@ -9,24 +9,20 @@ import 'package:smooth_app/helpers/strings_helper.dart';
 /// This separator is based on [NumberFormat], so it can be "." or "," depending
 /// on the user's language.
 ///
-/// Only languages with a space character (eg: French) as a group separator will
-/// have access to all features.
+/// It works if there are no group separator in the format, as it would be
+/// problematic with the `123,456.9` and both comma and dot.
 ///
-/// Also, if a separator is already displayed, it will be move to the new
+/// Also, if a separator is already displayed, it will be moved to the new
 /// position
 class DecimalSeparatorRewriter extends TextInputFormatter {
   DecimalSeparatorRewriter(NumberFormat format)
       : _decimalSeparator = format.symbols.DECIMAL_SEP,
         _separatorToReplace = _findSeparatorToReplace(format);
 
   final String _decimalSeparator;
-  final String? _separatorToReplace;
-
-  static String? _findSeparatorToReplace(NumberFormat format) {
-    if (!format.symbols.GROUP_SEP.isASpaceCharacter) {
-      return null;
-    }
+  final String _separatorToReplace;
 
+  static String _findSeparatorToReplace(NumberFormat format) {
     switch (format.symbols.DECIMAL_SEP) {
       case '.':
         return ',';
@@ -107,10 +103,9 @@ class DecimalSeparatorRewriter extends TextInputFormatter {
   /// Replaces a "." by a "," or a "," by a "." only if
   /// the group separator is an empty character
   String replaceSeparator(String newTextValue) {
-    if (_separatorToReplace != null &&
-        newTextValue.contains(_separatorToReplace!)) {
+    if (newTextValue.contains(_separatorToReplace)) {
       return newTextValue.replaceAll(
-        _separatorToReplace!,
+        _separatorToReplace,
         _decimalSeparator,
       );
     } else {

packages/smooth_app/lib/l10n/app_ar.arb

@@ -853,7 +853,7 @@
     "@are_you_sure": {
         "description": "Are you sure?"
     },
-    "knowledge_panel_text_source": "تعرف أكثر من خلال {source_name}",
+    "knowledge_panel_text_source": "تعرف أكثر من خلال {sourceName}",
     "@knowledge_panel_text_source": {
         "description": "Source field within a text knowledge panel.",
         "placeholders": {