feat: Enhance messaging and SAR marker functionalities

- Integrated SAR marker sending feature in MessagesTab with a dedicated dialog for user input.
- Updated message sending logic to default to the first available room if no contact is selected.
- Improved user feedback with SnackBars for connection issues and successful marker sends.
- Refactored contact selection to remove unused code and streamline the process.
- Added location fetching capabilities using Geolocator for SAR markers.
- Updated sample data with more relevant team names using emojis.
- Enhanced map markers to include rotation handling and improved display of contact information.
- Introduced color coding for location update age in map markers for better visibility.

lib/utils/sample_data_generator.dart

@@ -20,14 +20,14 @@ class SampleDataGenerator {
     final now = DateTime.now();
 
     final teamNames = [
-      'Alpha Team Lead',
-      'Bravo Scout',
-      'Charlie Medic',
-      'Delta Navigator',
-      'Echo Support',
-      'Foxtrot Runner',
-      'Golf Comms',
-      'Hotel Base',
+      '👮Police Lead',
+      '🚁Drone Operator',
+      '🧑🏻‍🚒Firefighter Alpha',
+      '🧑‍⚕️Medic Charlie',
+      '📡Command Delta',
+      '🚒Fire Engine',
+      '👨‍✈️Air Support',
+      '🧑‍💼Base Coordinator',
     ];
 
     final channelNames = [