Add "Success" to message logging levels, fixes for PHP 8.4, other preg_match fixes

The Logger/MessageLevel gets "success" as level 110 to something a bit
heigher than "ok" which is the general "OK" for anything ending without
an error. The "success" is currently only used in file uploads with the
java script ajax file uploader

Fix any "type $var = null" with correctly "?type $var = null" for PHP 8.4 (phphan)

Fix preg match no return catches for DB IO compare version and for language
look up.

4dev/tests/Logging/CoreLibsLoggingErrorMessagesTest.php

@@ -39,6 +39,11 @@ final class CoreLibsLoggingErrorMessagesTest extends TestCase
 				'str' => 'OK',
 				'expected' => 'ok',
 			],
+			'success' => [
+				'level' => 'success',
+				'str' => 'SUCCESS',
+				'expected' => 'success',
+			],
 			'info' => [
 				'level' => 'info',
 				'str' => 'INFO',