Improve UX when there are no Unsplash results

lang/en_us.php

@@ -138,4 +138,6 @@ define("STRINGS", [
     "delete" => "Delete",
     "new folder" => "New Folder",
     "new" => "New",
+    "search" => "Search",
+    "no results" => "No results.",
 ]);

lib/filepicker_unsplash.php

@@ -39,7 +39,7 @@ $images->
 $htmlout = "";
 
 if (count($images) == 0) {
-    $htmlout = "<span>" . lang("no results", false) . "</span>";
+    $htmlout = "<div class=\"card text-center\"><div class=\"card-body\"><i class=\"fas fa-search-minus\"></i> " . lang("no results", false) . "</div></div>";
 }
 
 $htmlout .= '<div class="card-columns">';