Remove shop

The items can be bought directly from the running game in the future.
The player can get free coins from the main and pause menu.

lib/widgets/get_coins.dart

@@ -0,0 +1,49 @@
+import 'package:firebase_admob/firebase_admob.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+import '../localizations.dart';
+import '../storage.dart';
+
+import 'menu_entry.dart';
+
+class GetCoins extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    final localizations = ChristmasCatsLocalizations.of(context);
+
+    return MenuEntry(
+      text: localizations.getCoins,
+      onTap: () {
+        final scaffold = Scaffold.of(context);
+        scaffold.showSnackBar(SnackBar(
+          content: Text(localizations.adLoading),
+          // Show it until the ad is loaded
+          duration: Duration(minutes: 1),
+        ));
+
+        final ad = RewardedVideoAd.instance;
+        ad.listener = (event, {rewardAmount, rewardType}) {
+          scaffold.removeCurrentSnackBar();
+          if (event == RewardedVideoAdEvent.loaded) {
+            ad.show();
+          } else if (event == RewardedVideoAdEvent.failedToLoad) {
+            scaffold.showSnackBar(SnackBar(
+              content: Text(localizations.noAds),
+              duration: const Duration(seconds: 2),
+            ));
+          } else if (event == RewardedVideoAdEvent.rewarded) {
+            storage.addCoins(rewardAmount);
+          }
+        };
+
+        ad.load(
+          adUnitId: kReleaseMode
+              ? 'ca-app-pub-4129701777413448/6712208196'
+              : RewardedVideoAd.testAdUnitId,
+          targetingInfo: MobileAdTargetingInfo(),
+        );
+      },
+    );
+  }
+}