added comment section on card details to avoid loading the card comment activities from the server

- and added to show only the activities a card

- to display the card comments a connection to the server was needed to get the activities of the card comments, now, it's not necessary
- also performance relevant. until now there were a lot of activities loaded, now only of the current card

server/migrations.js

@@ -1457,3 +1457,19 @@ Migrations.add('remove-unused-planning-poker', () => {
     noValidateMulti,
   );
 });
+
+Migrations.add('remove-user-profile-hiddenSystemMessages', () => {
+  Users.update(
+    {
+      "profile.hiddenSystemMessages": {
+        $exists: true,
+      },
+    },
+    {
+      $unset: {
+        "profile.hiddenSystemMessages": 1,
+      },
+    },
+    noValidateMulti,
+  );
+});