add use strict to js files

src/Packagist/WebBundle/Resources/public/js/layout.js

@@ -1,3 +1,5 @@
+"use strict";
+
 /*
     Adjust width for packades data
 */

src/Packagist/WebBundle/Resources/public/js/search.js

@@ -1,3 +1,5 @@
+"use strict";
+
 (function ($) {
     var form = $('form#search-form'),
         showResults,