[IMP] web: 'Not Archived' becomes 'Active', 'Not published' becomes 'Unpublished'

Another reason why it’s better to change ‘not archived’ into ‘active’ is
because ‘active’ is the functional name of this field in the filter list in list view.

For the rest, it’s just a better en_US way of saying it.

addons/website/static/src/js/website.backend.js

@@ -19,7 +19,7 @@ var WidgetWebsiteButton = form_common.AbstractField.extend({
                   .removeClass('text-danger')
                   .addClass('text-success');
         } else {
-            $value.html(_t('Not Published'))
+            $value.html(_t('Unpublished'))
                   .removeClass('text-success')
                   .addClass('text-danger');
         }