add dart client to packages

packages/dart_client/pubspec.yaml

@@ -0,0 +1,36 @@
+name: stream_chat
+homepage: https://getstream.io/
+description: The official Dart client for Stream Chat, a service for building chat applications.
+version: 0.2.23+1
+repository: https://github.com/GetStream/stream-chat-dart
+issue_tracker: https://github.com/GetStream/stream-chat-dart/issues
+
+environment:
+  sdk: ">=2.2.2 <3.0.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+  json_annotation: ^3.0.1
+  shared_preferences: ^0.5.7+3
+  logging: ^0.11.4
+  dio: ^3.0.10
+  web_socket_channel: ^1.1.0
+  uuid: ^2.2.2
+  async: ^2.4.1
+  stream_channel: ^2.0.0
+  moor: ^3.3.1
+  path_provider: ^1.6.10
+  path: ^1.6.4
+  rxdart: ^0.24.1
+  collection: ^1.14.12
+  sqlite3_flutter_libs: ^0.3.0
+
+dev_dependencies:
+  build_runner: ^1.10.0
+  json_serializable: ^3.3.0
+  moor_generator: ^3.1.0
+  flutter_test:
+    sdk: flutter
+  pedantic: ^1.8.0+1
+  mockito: ^4.1.1