Added message for default active filters

At the moment when the around page loads it has some filters been applied. We should let users using assitive devices that's the case.

templates/web/base/reports/_list-filter-status.html

@@ -1,5 +1,6 @@
 [% SET show_all_states = c.cobrand.filter_show_all_states OR (c.user_exists AND (c.user.is_superuser OR c.user.belongs_to_body(body.id))) %]
 
+<div id="filter-announcement" class="screen-reader-only" role="alert">Information: Filters in use. The current view is customized based on selected filters.</div>
 <select class="form-control js-multiple" name="status" id="statuses" multiple
     data-all="[% loc('All') %]"
     [% IF show_all_states %]