Perform capabilities check on liking/unliking

Finishes implementation of Issue #93

lib/controls/timeline/interactions_bar_control.dart

@@ -161,12 +161,15 @@ class _InteractionsBarControlState extends State<InteractionsBarControl> {
   }
 
   Widget buildLikeButton() {
+    final canReact = widget.entry.getCanReact();
+    final tooltip =
+        canReact.canDo ? 'Press to toggle like/unlike' : canReact.reason;
     return buildButton(
       isFavorited ? Icons.thumb_up : Icons.thumb_up_outlined,
       likes,
       true,
-      'Press to toggle like/unlike',
+      tooltip,
-      () async => await toggleFavorited(),
+      canReact.canDo ? () async => await toggleFavorited() : null,
     );
   }
 

lib/utils/interaction_availability_util.dart

@@ -27,12 +27,31 @@ extension InteractionAvailabilityExtension on TimelineEntry {
       );
     }
 
-    return InteractionCapabilityResult(
+    return const InteractionCapabilityResult(
       canDo: true,
       reason: "Can comment on item",
     );
   }
 
+  InteractionCapabilityResult getCanReact() {
+    final settingsService = getIt<SettingsService>();
+    final nc = settingsService.networkCapabilities
+        .getCapabilities(networkInfo.network);
+
+    if (!nc.react) {
+      return InteractionCapabilityResult(
+        canDo: false,
+        reason:
+            "User disabled reacting on ${networkInfo.network.labelName} items. Go into settings to change.",
+      );
+    }
+
+    return const InteractionCapabilityResult(
+      canDo: true,
+      reason: "Can react on item",
+    );
+  }
+
   InteractionCapabilityResult getIsReshareable(bool isMine) {
     if (isMine) {
       return const InteractionCapabilityResult(