Refactor contact handling and other improvments (#317)

* Refactor contact filtering and improve localization strings; enhance path trace handling

* Add localization for new CLI commands and update existing strings

* Enhance contact handling and UI updates across multiple screens
add unfiltered contact access and improve last seen resolution

* Add polling interval configuration and improve contact handling

* Reorder command constants for better organization and clarity

* Refactor contact handling by removing unnecessary mapping and improving clarity across multiple screens

* Moved RadioStatsIconButton in chat screen for improved UI consistency

* Added indicators to AppBar for channels

* Ignore contacts with self public key in contact handling

* Simplify path removal logic and clean up unused imports in path management dialog

* Enhance path hop resolution by adding distance checks to improve candidate selection accuracy

* Remove unnecessary reset of radio stats poll reference count in polling interval setter

lib/screens/chat_screen.dart

@@ -294,6 +294,7 @@ class _ChatScreenState extends State<ChatScreen> {
             tooltip: context.l10n.chat_pathManagement,
             onPressed: () => _showPathHistory(context),
           ),
+          const RadioStatsIconButton(),
           Consumer<MeshCoreConnector>(
             builder: (context, connector, _) {
               return PopupMenuButton<String>(
@@ -366,7 +367,6 @@ class _ChatScreenState extends State<ChatScreen> {
               );
             },
           ),
-          const RadioStatsIconButton(),
         ],
       ),
       body: Consumer<MeshCoreConnector>(