Refactor localization keys for "neighbors" terminology across multiple languages

- Updated localization keys from "neighbours" to "neighbors" in the following files:
  - app_localizations_bg.dart
  - app_localizations_de.dart
  - app_localizations_en.dart
  - app_localizations_es.dart
  - app_localizations_fr.dart
  - app_localizations_it.dart
  - app_localizations_nl.dart
  - app_localizations_pl.dart
  - app_localizations_pt.dart
  - app_localizations_ru.dart
  - app_localizations_sk.dart
  - app_localizations_sl.dart
  - app_localizations_sv.dart
  - app_localizations_uk.dart
  - app_localizations_zh.dart
- Updated corresponding ARB files to reflect the changes in keys.
- Renamed the NeighboursScreen to NeighborsScreen in the chat and repeater hub screens for consistency.

lib/l10n/app_localizations_it.dart

@@ -1676,10 +1676,10 @@ class AppLocalizationsIt extends AppLocalizations {
   String get repeater_cliSubtitle => 'Invia comandi al ripetitore';
 
   @override
-  String get repeater_neighbours => 'Vicini';
+  String get repeater_neighbors => 'Vicini';
 
   @override
-  String get repeater_neighboursSubtitle =>
+  String get repeater_neighborsSubtitle =>
       'Visualizza vicini di salto pari a zero.';
 
   @override
@@ -2380,7 +2380,7 @@ class AppLocalizationsIt extends AppLocalizations {
   }
 
   @override
-  String get neighbors_repeatersNeighbours => 'Ripetitori Vicini';
+  String get neighbors_repeatersNeighbors => 'Ripetitori Vicini';
 
   @override
   String get neighbors_noData => 'Nessun dato sugli vicini disponibile.';