Add visits metric in summary

Author: davquar

lib/l10n/app_en.arb

@@ -15,6 +15,10 @@
   "@visitors": {
     "description": "Unique visitors"
   },
+  "visits": "Visits",
+  "@visitors": {
+    "description": "Unique sessions"
+  },
   "bounces": "Bounces",
   "@bounces": {
     "description": "Bounces"

lib/models/api/stats.dart

@@ -1,15 +1,18 @@
 import 'package:halfdot/models/api/common.dart';
 
 class StatsResponse implements ApiModel {
-  StatsResponse(this.pageViews, this.visitors, this.bounces, this.totalTime);
+  StatsResponse(
+      this.pageViews, this.visits, this.visitors, this.bounces, this.totalTime);
 
   StatsResponse.fromJson(Map<String, dynamic> json)
       : pageViews = json['pageviews']['value'],
+        visits = json['visits']['value'],
         visitors = json['visitors']['value'],
         bounces = json['bounces']['value'],
         totalTime = json['totaltime']['value'];
 
   final int pageViews;
+  final int visits;
   final int visitors;
   final int bounces;
   final int totalTime;

lib/screens/website_statistics.dart

@@ -115,6 +115,15 @@ class _WebsiteStatisticsPageState extends State<WebsiteStatisticsPage> {
                                           .pageViews),
                                     ],
                                   ),
+                                  Column(children: <Widget>[
+                                    Text(
+                                      snapshot.data!.visits.toString(),
+                                      style: Theme.of(context)
+                                          .textTheme
+                                          .titleLarge,
+                                    ),
+                                    Text(AppLocalizations.of(context)!.visits),
+                                  ]),
                                   Column(children: <Widget>[
                                     Text(
                                       snapshot.data!.visitors.toString(),