Fixed: React error displaying a search result for an existing movie

Co-Authored-By: Mark McDowall <markus101@users.noreply.github.com>

frontend/src/AddMovie/AddNewMovie/AddNewMovieSearchResult.css

@@ -1,10 +1,15 @@
 .searchResult {
-  display: flex;
+  position: relative;
   margin: 20px 0;
   padding: 20px;
   width: 100%;
-  background-color: $white;
   color: inherit;
+}
+
+.underlay {
+  @add-mixin cover;
+
+  background-color: $white;
   transition: background 500ms;
 
   &:hover {
@@ -14,6 +19,13 @@
   }
 }
 
+.overlay {
+  @add-mixin linkOverlay;
+
+  position: relative;
+  display: flex;
+}
+
 .poster {
   flex: 0 0 170px;
   margin-right: 20px;