TF-654 Show the progress of download attachment on web

lib/features/base/mixin/app_loader_mixin.dart

@@ -2,6 +2,7 @@
 import 'package:core/core.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
+import 'package:percent_indicator/circular_percent_indicator.dart';
 import 'package:percent_indicator/linear_percent_indicator.dart';
 
 mixin AppLoaderMixin {
@@ -21,6 +22,18 @@ mixin AppLoaderMixin {
           backgroundColor: AppColor.colorBgMailboxSelected));
   }
 
+  Widget circularPercentLoadingWidget(double percent) {
+    return Center(
+        child: CircularPercentIndicator(
+          percent: percent > 1.0 ? 1.0 : percent,
+          backgroundColor: AppColor.colorBgMailboxSelected,
+          progressColor: AppColor.primaryColor,
+          lineWidth: 3,
+          radius: 14,
+        )
+    );
+  }
+
   Widget horizontalPercentLoadingWidget(double percent) {
     return Center(
         child: LinearPercentIndicator(