Add filter that takes care of mastodon posts with link preview having duplicate images

lib/controls/search_result_status_control.dart

@@ -127,6 +127,14 @@ class _SearchResultStatusControlState extends State<SearchResultStatusControl> {
     if (items.isEmpty) {
       return const SizedBox();
     }
+
+    // A Link Preview with only one media attachment will have a duplicate image
+    // even though it points to different resources server side. So we don't
+    // want to render it twice.
+    if (widget.status.linkPreviewData != null && items.length == 1) {
+      return const SizedBox();
+    }
+
     return SizedBox(
         height: 250.0,
         child: ListView.separated(

lib/controls/timeline/flattened_tree_entry_control.dart

@@ -228,6 +228,14 @@ class _StatusControlState extends State<FlattenedTreeEntryControl> {
     if (items.isEmpty) {
       return const SizedBox();
     }
+
+    // A Link Preview with only one media attachment will have a duplicate image
+    // even though it points to different resources server side. So we don't
+    // want to render it twice.
+    if (entry.linkPreviewData != null && items.length == 1) {
+      return const SizedBox();
+    }
+
     return SizedBox(
         height: ResponsiveSizesCalculator(context).maxThumbnailHeight,
         child: ListView.separated(