CAKE-356 | fixed _fetchEmojiFromUri method in the main.dart and fetchYatAddress method in the yat_record.dart

lib/main.dart

@@ -228,11 +228,11 @@ class AppState extends State<App> with SingleTickerProviderStateMixin {
 
   void _fetchEmojiFromUri(Uri uri, YatStore yatStore) {
     final queryParameters = uri.queryParameters;
-    if (queryParameters == null || queryParameters.isEmpty) {
+    if (queryParameters?.isEmpty ?? true) {
       return;
     }
     final emoji = queryParameters['eid'];
-    if (emoji == null || emoji.isEmpty) {
+    if (emoji?.isEmpty ?? true) {
       return;
     }
     yatStore.emoji = emoji;

lib/yat/yat_record.dart

@@ -20,5 +20,10 @@ Future<String> fetchYatAddress(String emojiId, String ticker) async {
   }
 
   final yatAddress = result.first['data'] as String;
+
+  if (yatAddress?.isEmpty ?? true) {
+    return '';
+  }
+
   return yatAddress;
 }