Beeep/remove sad faces (#1255)

* Replace sad face with searching image

* Change css variable name

* Added aria-hidden="true" to images

* Run prettier

src/scss/vault.scss

@@ -303,6 +303,12 @@ app-root {
       text-align: center;
       padding: 0 10px;
 
+      .no-items-image {
+        @include themify($themes) {
+          content: url("../images/search-desktop" + themed("svgSuffix"));
+        }
+      }
+
       .fa {
         margin-bottom: 10px;