MDL-80005 core: Emit deprecation notices for params

Most params are formally deprecated here. This was originally planned
for MDL-80042, but I realised that having an emit, and final param is a
very useful option going forward.

This patch also moves the is_deprecated(), and related methods to the
\core\deprecated attribute.

mod/workshop/classes/external.php

@@ -1508,7 +1508,7 @@ class mod_workshop_external extends external_api {
                     $data->feedbackauthor_editor['text'] = $wsdata['value'];
                     break;
                 case 'feedbackauthorformat':
-                    $data->feedbackauthor_editor['format'] = clean_param($wsdata['value'], PARAM_FORMAT);
+                    $data->feedbackauthor_editor['format'] = clean_param($wsdata['value'], PARAM_ALPHANUMEXT);
                     break;
                 case 'feedbackauthorinlineattachmentsid':
                     $data->feedbackauthor_editor['itemid'] = clean_param($wsdata['value'], PARAM_INT);