Refactor message handling and enhance BLE connection management

- Cleaned up message formatting in MessagesTab for better readability.
- Improved SAR message parsing to include optional inline messages.
- Updated BLE connection manager to monitor RSSI values and added callback for RSSI updates.
- Adjusted drawing message parser to remove sender name from JSON and extract it from packet metadata.
- Enhanced drawing toolbar to reflect changes in message creation without sender name.
- Ensured consistent error handling and logging across BLE operations.

lib/utils/drawing_message_parser.dart

@@ -12,8 +12,9 @@ class DrawingMessageParser {
   }
 
   /// Parse drawing message text into MapDrawing object
+  /// senderName should be extracted from packet metadata
   /// Returns null if parsing fails
-  static MapDrawing? parseDrawingMessage(String text) {
+  static MapDrawing? parseDrawingMessage(String text, {String? senderName}) {
     if (!isDrawingMessage(text)) {
       return null;
     }
@@ -25,17 +26,18 @@ class DrawingMessageParser {
       // Parse JSON
       final json = jsonDecode(jsonStr) as Map<String, dynamic>;
 
-      // Use compact network format parser
-      return MapDrawing.fromNetworkJson(json);
+      // Use ultra-compact network format parser
+      // Sender name comes from packet metadata, not JSON
+      return MapDrawing.fromNetworkJson(json, senderName: senderName);
     } catch (e) {
       return null;
     }
   }
 
   /// Create drawing message text from MapDrawing object
-  /// Includes sender name in the message
-  static String createDrawingMessage(MapDrawing drawing, String senderName) {
-    final json = drawing.toNetworkJson(senderName);
+  /// Sender will be determined from packet metadata on receiving end
+  static String createDrawingMessage(MapDrawing drawing) {
+    final json = drawing.toNetworkJson();
     final jsonStr = jsonEncode(json);
     return '$prefix$jsonStr';
   }