🐛 Fix compability issue on web platform

lib/services/udid.dart

@@ -0,0 +1 @@
+export 'udid.native.dart' if (dart.library.html) 'udid.web.dart';

lib/services/udid.native.dart

@@ -0,0 +1,5 @@
+import 'package:flutter_udid/flutter_udid.dart';
+
+Future<String> getUdid() async {
+  return await FlutterUdid.consistentUdid;
+}

lib/services/udid.web.dart

@@ -0,0 +1,11 @@
+import 'dart:convert';
+
+import 'package:crypto/crypto.dart';
+import 'package:web/web.dart';
+
+Future<String> getUdid() async {
+  final userAgent = window.navigator.userAgent;
+  final bytes = utf8.encode(userAgent);
+  final hash = sha256.convert(bytes);
+  return hash.toString();
+}