Added uploader javascript to the top of the cms page so the reducer is added whenever the cms is loaded.

_config/config.yml

@@ -0,0 +1,3 @@
+SilverStripe\Admin\LeftAndMain:
+  extra_requirements_javascript:
+    - 'colymba/gridfield-bulk-editing-tools: client/dist/js/main.js'

src/BulkUploader/BulkUploader.php

@@ -293,8 +293,8 @@ class BulkUploader implements GridField_HTMLProvider, GridField_URLHandler
             'Colspan' => (count($gridField->getColumns() ?? [])),
             'UploadField' => $uploadField->Field() // call ->Field() to get requirements in right order
         ));
-
-        Requirements::javascript('colymba/gridfield-bulk-editing-tools:client/dist/js/main.js');
+        //This one is no longer needed since the javascript is now loaded at the top of the cms
+        //Requirements::javascript('colymba/gridfield-bulk-editing-tools:client/dist/js/main.js');
         Requirements::css('colymba/gridfield-bulk-editing-tools:client/dist/styles/main.css');
         Requirements::add_i18n_javascript('colymba/gridfield-bulk-editing-tools:client/lang');