TF-1714 Add ThreadViewLoadingBar widget

(cherry picked from commit 5f18ad49d9d9ca8e077716df7f0aa9567275dcd7)

lib/features/thread/presentation/widgets/thread_view_bottom_loading_bar_widget.dart

@@ -0,0 +1,33 @@
+import 'package:core/presentation/state/failure.dart';
+import 'package:core/presentation/state/success.dart';
+import 'package:dartz/dartz.dart';
+import 'package:flutter/material.dart';
+import 'package:tmail_ui_user/features/base/widget/cupertino_loading_widget.dart';
+import 'package:tmail_ui_user/features/thread/domain/state/load_more_emails_state.dart';
+import 'package:tmail_ui_user/features/thread/domain/state/search_more_email_state.dart';
+
+class ThreadViewBottomLoadingBarWidget extends StatelessWidget {
+
+  final Either<Failure, Success> viewState;
+
+  const ThreadViewBottomLoadingBarWidget({
+    super.key,
+    required this.viewState,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return viewState.fold(
+      (failure) => const SizedBox.shrink(),
+      (success) {
+        if (success is SearchingMoreState || success is LoadingMoreEmails) {
+          return const Padding(
+            padding: EdgeInsetsDirectional.only(bottom: 16),
+            child: CupertinoLoadingWidget());
+        } else {
+          return const SizedBox.shrink();
+        }
+      }
+    );
+  }
+}

lib/features/thread/presentation/widgets/thread_view_loading_bar_widget.dart

@@ -0,0 +1,33 @@
+import 'package:core/presentation/state/failure.dart';
+import 'package:core/presentation/state/success.dart';
+import 'package:dartz/dartz.dart';
+import 'package:flutter/material.dart';
+import 'package:tmail_ui_user/features/base/widget/cupertino_loading_widget.dart';
+import 'package:tmail_ui_user/features/thread/domain/state/get_all_email_state.dart';
+import 'package:tmail_ui_user/features/thread/domain/state/search_email_state.dart';
+
+class ThreadViewLoadingBarWidget extends StatelessWidget {
+
+  final Either<Failure, Success> viewState;
+
+  const ThreadViewLoadingBarWidget({
+    super.key,
+    required this.viewState,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return viewState.fold(
+      (failure) => const SizedBox.shrink(),
+      (success) {
+        if (success is SearchingState || success is GetAllEmailLoading) {
+          return const Padding(
+            padding: EdgeInsetsDirectional.only(top: 16),
+            child: CupertinoLoadingWidget());
+        } else {
+          return const SizedBox.shrink();
+        }
+      }
+    );
+  }
+}