chore: apply linter to the various example and test directories (#550)

* chore: remove examples and tests from analysis exclusion

* chore: apply linter fixes to stream_chat_flutter_core/example/main.dart

* chore: apply linter fixes to stream_chat_flutter/example/main.dart

* chore: apply linter fixes to stream_chat_persistence/example/main.dart

* chore: apply linter fixes to stream_chat/example/main.dart

* chore: apply linter fixes to stream_chat_flutter/example/split_view.dart

* chore: renamte tutorial files per linter

* chore: apply linter fixes to tutorial_part_1.dart

* chore: apply linter fixes to tutorial_part_2.dart

* chore: apply linter fixes to tutorial_part_3.dart

* chore: apply linter fixes to tutorial_part_4.dart

* chore: apply linter fixes to tutorial_part_5.dart

* chore: make a widget const in tutorial_part_5.dart

* chore: apply linter fixes to tutorial_part_6.dart

* chore: sort and update dependencies in stream_chat_persistence/example/pubspec.yaml

* chore: sort and update dependencies in stream_chat_flutter_core/example/pubspec.yaml

* chore: sort and update dependencies in stream_chat_flutter/example/pubspec.yaml

* chore: sort dependencies in stream_chat_flutter/example/pubspec.yaml

* chore: apply linter fixes to channel_test.dart

* chore: apply linter fixes to client_test.dart

* chore: apply linter fixes to client_test.dart, stream_http_client_test.dart, and token_manager_test.dart

* chore: apply linter fixes to filter_test.dart

* chore: apply linter fixes to reaction_test.dart

* chore: apply linter fixes to chat_persistence_client_test.dart

* chore: apply linter fixes to channel_image_test.dart

* chore: apply linter fixes to deleted_message_test.dart

* chore: apply linter fixes to full_screen_media_test.dart

* chore: apply linter fixes to gallery_footer_theme_test.dart

* chore: apply linter fixes to gallery_header_theme_test.dart

* chore: apply linter fixes to message_text_test.dart

* chore: apply linter fixes to reaction_bubble_test.dart

* chore: apply linter fixes to system_message_test.dart

* chore: apply linter fixes to typing_indicator_test.dart

* chore: apply linter fixes to channel_list_core_test.dart

* chore: apply linter fixes to channels_bloc_test.dart

* chore: apply linter fixes to lazy_load_scroll_view_test.dart

* chore: apply linter fixes to channel_matcher.dart

* chore: apply linter fixes to message_matcher.dart

* chore: apply linter fixes to users_matcher.dart

* chore: apply linter fixes to message_list_core_test.dart

* chore: apply linter fixes to message_search_bloc_test.dart

* chore: apply linter fixes to message_search_list_core_test.dart

* chore: apply linter fixes to stream_channel_test.dart

* chore: apply linter fixes to stream_chat_core_test.dart

* chore: apply linter fixes to user_list_core_test.dart

* chore: apply linter fixes to channel_query_dao_test.dart, message_mapper_test.dart, user_mapper_test.dart, and users_bloc_test.dart

* chore: apply some missed dartfmt

* test: regenerate failinggolden test

packages/stream_chat/test/src/core/http/stream_http_client_test.dart

@@ -57,7 +57,7 @@ void main() {
   });
 
   test(
-    'connectionIdInterceptor should be added if connectionIdManager is provided',
+    '''connectionIdInterceptor should be added if connectionIdManager is provided''',
     () {
       const apiKey = 'api-key';
       final client = StreamHttpClient(

packages/stream_chat/test/src/core/http/token_manager_test.dart

@@ -45,7 +45,7 @@ void main() {
   });
 
   test(
-    '`setTokenOrProvider` should throw if both token and provider is not provided',
+    '''`setTokenOrProvider` should throw if both token and provider is not provided''',
     () async {
       expect(tokenManager.userId, isNull);
 

packages/stream_chat/test/src/core/models/filter_test.dart

@@ -192,7 +192,7 @@ void main() {
       test('custom with no operator', () {
         const key = 'testKey';
         const values = ['testValue'];
-        final filter = Filter.custom(key: key, value: values);
+        const filter = Filter.custom(key: key, value: values);
         final encoded = json.encode(filter);
         expect(
           encoded,

packages/stream_chat/test/src/core/models/reaction_test.dart

@@ -13,7 +13,7 @@ void main() {
       expect(reaction.type, 'wow');
       expect(
         reaction.user?.toJson(),
-        User(id: '2de0297c-f3f2-489d-b930-ef77342edccf', extraData: {
+        User(id: '2de0297c-f3f2-489d-b930-ef77342edccf', extraData: const {
           'image': 'https://randomuser.me/api/portraits/women/45.jpg',
           'name': 'Daisy Morgan'
         }).toJson(),
@@ -28,7 +28,8 @@ void main() {
         messageId: '76cd8c82-b557-4e48-9d12-87995d3a0e04',
         createdAt: DateTime.parse('2020-01-28T22:17:31.108742Z'),
         type: 'wow',
-        user: User(id: '2de0297c-f3f2-489d-b930-ef77342edccf', extraData: {
+        user:
+            User(id: '2de0297c-f3f2-489d-b930-ef77342edccf', extraData: const {
           'image': 'https://randomuser.me/api/portraits/women/45.jpg',
           'name': 'Daisy Morgan'
         }),