Refactor SAR marker handling and add template management

- Updated CompassSarList and DetailedCompassDialog to use marker.displayName instead of marker.type.displayName.
- Enhanced DrawingLayer and DrawingMarkersLayer to support simple mode for drawing visibility and interaction.
- Added toggle switches in DrawingToolbar for showing/hiding received drawings and SAR markers.
- Modified MapMarkers to utilize custom emojis and display names for markers.
- Introduced RecipientSelectorSheet for selecting message recipients with search functionality.
- Refactored SarUpdateSheet to use SAR templates instead of marker types, allowing for emoji and name customization.
- Created SarTemplateEditDialog for adding and editing SAR templates with color selection and preview.

lib/providers/drawing_provider.dart

@@ -20,6 +20,8 @@ class DrawingProvider with ChangeNotifier {
   // Drawing state
   DrawingMode _drawingMode = DrawingMode.none;
   Color _selectedColor = DrawingColors.palette[0];
+  bool _showReceivedDrawings = true;
+  bool _showSarMarkers = true;
 
   // Completed drawings
   final List<MapDrawing> _drawings = [];
@@ -32,7 +34,11 @@ class DrawingProvider with ChangeNotifier {
   // Getters
   DrawingMode get drawingMode => _drawingMode;
   Color get selectedColor => _selectedColor;
-  List<MapDrawing> get drawings => List.unmodifiable(_drawings);
+  bool get showReceivedDrawings => _showReceivedDrawings;
+  bool get showSarMarkers => _showSarMarkers;
+  List<MapDrawing> get drawings => _showReceivedDrawings
+      ? List.unmodifiable(_drawings)
+      : List.unmodifiable(_drawings.where((d) => !d.isReceived).toList());
   MapDrawing? get currentDrawing => _currentDrawing;
   List<LatLng> get currentLinePoints => List.unmodifiable(_currentLinePoints);
   LatLng? get rectangleStartPoint => _rectangleStartPoint;
@@ -59,6 +65,18 @@ class DrawingProvider with ChangeNotifier {
     notifyListeners();
   }
 
+  /// Toggle visibility of received drawings
+  void toggleReceivedDrawings() {
+    _showReceivedDrawings = !_showReceivedDrawings;
+    notifyListeners();
+  }
+
+  /// Toggle visibility of SAR markers
+  void toggleSarMarkers() {
+    _showSarMarkers = !_showSarMarkers;
+    notifyListeners();
+  }
+
   /// Start drawing a line
   void startLine(LatLng point) {
     if (_drawingMode != DrawingMode.line) return;