feat(database, web): migrate web to js_interop to be compatible with WASM

packages/firebase_database/firebase_database_web/lib/firebase_database_web.dart

@@ -5,30 +5,24 @@
 library firebase_database_web;
 
 import 'dart:async';
-import 'dart:js_util' as util;
+import 'dart:js_interop';
 
 import 'package:firebase_core/firebase_core.dart';
 import 'package:firebase_core_web/firebase_core_web.dart';
-import 'package:firebase_database_platform_interface/firebase_database_platform_interface.dart';
-import 'package:flutter_web_plugins/flutter_web_plugins.dart';
 import 'package:firebase_core_web/firebase_core_web_interop.dart'
     as core_interop;
+import 'package:firebase_database_platform_interface/firebase_database_platform_interface.dart';
+import 'package:flutter_web_plugins/flutter_web_plugins.dart';
+
 import 'src/interop/database.dart' as database_interop;
 
 part './src/data_snapshot_web.dart';
-
 part './src/database_event_web.dart';
-
 part './src/database_reference_web.dart';
-
 part './src/ondisconnect_web.dart';
-
 part './src/query_web.dart';
-
 part './src/transaction_result_web.dart';
-
 part './src/utils/exception.dart';
-
 part './src/utils/snapshot_utils.dart';
 
 /// Web implementation for [DatabasePlatform]

packages/firebase_database/firebase_database_web/lib/src/interop/data_snapshot_interop.dart

@@ -5,31 +5,32 @@
 part of firebase.database_interop;
 
 @JS('DataSnapshot')
+@staticInterop
 @anonymous
-abstract class DataSnapshotJsImpl {
-  external String get key;
+abstract class DataSnapshotJsImpl {}
 
-  external ReferenceJsImpl get ref;
+extension DataSnapshotJsImpl$ on DataSnapshotJsImpl {
+  external JSString get key;
 
-  external dynamic /* string | num | null*/ get priority;
+  external ReferenceJsImpl get ref;
 
-  external int get size;
+  external JSAny? /* JSString | num | null*/ get priority;
 
-  external DataSnapshotJsImpl child(String path);
+  external JSNumber get size;
 
-  external bool exists();
+  external DataSnapshotJsImpl child(JSString path);
 
-  external dynamic exportVal();
+  external JSBoolean exists();
 
-  external bool forEach(void Function(dynamic) action);
+  external JSAny? exportVal();
 
-  external dynamic getPriority();
+  external JSAny forEach(JSFunction action);
 
-  external bool hasChild(String path);
+  external JSBoolean hasChild(JSString path);
 
-  external bool hasChildren();
+  external JSBoolean hasChildren();
 
-  external Object toJSON();
+  external JSObject toJSON();
 
-  external dynamic val();
+  external JSAny? val();
 }