fix: [warnings] added tlp:clear and tlp:amber+strict to the valid tlp tags

- Clearly, the new tags should be accomodated...
- ... though these ones do not spark joy.

app/Lib/EventWarning/DefaultWarning.php

@@ -63,7 +63,7 @@ class DefaultWarning
     {
         $lowerTagName = trim(strtolower($tagName));
         if (substr($lowerTagName, 0, 4) === 'tlp:') {
-            if (!in_array($lowerTagName, ['tlp:white', 'tlp:green', 'tlp:amber', 'tlp:red', 'tlp:ex:chr'], true)) {
+            if (!in_array($lowerTagName, ['tlp:white', 'tlp:green', 'tlp:amber', 'tlp:red', 'tlp:ex:chr', 'tlp:clear', 'tlp:amber+strict'], true)) {
                 $warnings['TLP'][] = __('Unknown TLP tag, please refer to the TLP taxonomy as to what is valid, otherwise filtering rules created by your partners may miss your intent.');
             } else if ($lowerTagName !== $tagName) {
                 $warnings['TLP'][] = __('TLP tag with invalid formatting: Make sure that you only use TLP tags from the taxonomy. Custom tags with invalid capitalisation, white spaces or other artifacts will break synchronisation and filtering rules intended for the correct taxonomy derived tags.');