preview gif for references search.

services/web/public/stylesheets/app/editor.less

@@ -247,6 +247,17 @@
 	background-color: transparent;
 }
 .references-search-modal {
+	.references-search-upgrade-prompt {
+		.preview-gif {
+			align-content: center;
+			width: 100%;
+		}
+		.message {
+			margin-top: 15px;
+			text-align: center;
+			font-weight: bold;
+		}
+	}
 	.search-form {
 		input {
 			//width: 85%;