search: Add search_pill_widget.js.

Also adds the file to the static asset pipeline.
search_pill_widget.js will be used to access the pills object for
the search query box. It will act in a similar way to
compose_pm_pill.js. Why is this needed: Consider you've initiated
a pills object in search.js for the search query box. Now you want to
also access that pills object to pre-populate pills after a reload in
hashchange.js. search_pill_widget.js makes this easy without the use
of events.

.eslintrc.json

@@ -194,7 +194,8 @@
         "panels": false,
         "PerfectScrollbar": false,
         "search_pill": false,
-        "Sortable": false
+        "Sortable": false,
+        "search_pill_widget": false
     },
     "plugins": [
         "eslint-plugin-empty-returns"

static/js/bundles/app.js

@@ -191,6 +191,7 @@ import "js/compose_ui.js";
 import "js/panels.js";
 import 'js/settings_ui.js';
 import 'js/search_pill.js';
+import 'js/search_pill_widget.js';
 
 // Import Styles
 

static/js/search_pill_widget.js

@@ -0,0 +1,11 @@
+var search_pill_widget = (function () {
+
+var exports = {};
+return exports;
+}());
+
+if (typeof module !== 'undefined') {
+    module.exports = search_pill_widget;
+}
+
+window.search_pill_widget = search_pill_widget;