CAKE-192 | implemented unstoppable domain address to the app

lib/entities/unstoppable_domain_address.dart

@@ -0,0 +1,22 @@
+import 'package:flutter/services.dart';
+
+const channel = MethodChannel('com.cakewallet.cake_wallet/unstoppable-domain');
+
+Future<String> fetchUnstoppableDomainAddress(String domain, String ticker) async {
+  String address;
+
+  try {
+    address = await channel.invokeMethod(
+        'getUnstoppableDomainAddress',
+        <String, String> {
+          'domain' : domain,
+          'ticker' : ticker
+        }
+    );
+  } catch (e) {
+    print('Unstoppable domain error: ${e.toString()}');
+    address = '';
+  }
+
+  return address;
+}