hide server ACL events from timeline by default, introduce setting to show them

lib/widgets/renderers/event.dart

@@ -90,12 +90,13 @@ class const EventRenderer(
 
     if (event == null) return SizedBox.shrink();
 
-    final hideMembershipEvents = (ref
+    final (hideMembershipEvents, hideServerAclEvents) = ref
         .watch(SettingsController.provider)
         .maybeWhen(
-          orElse: () => false,
-          data: (settings) => settings.hideMembershipEvents,
-        ));
+          orElse: () => (false, true),
+          data: (settings) =>
+              (settings.hideMembershipEvents, settings.hideServerAclEvents),
+        );
 
     // Knocks and their outcomes stay visible, as moderators need to act on them
     if (hideMembershipEvents &&
@@ -106,6 +107,10 @@ class const EventRenderer(
       return SizedBox.shrink();
     }
 
+    if (hideServerAclEvents && event.content is ServerACLContent) {
+      return SizedBox.shrink();
+    }
+
     final isGrouped =
         (previousEvent?.isShownAsMessage ?? false) &&
         event.sender == previousEvent?.sender &&