refactor: cleanup Security (codeigniter4#9972)

* Remove deprecated items in Security

* Reorder methods with public, then protected, and private as last

* Add static return type to `verify`

* Refactor Security class

Author: paulbalandan

rector.php

@@ -149,7 +149,6 @@
             __DIR__ . '/system/HTTP/CURLRequest.php',
             __DIR__ . '/system/HTTP/DownloadResponse.php',
             __DIR__ . '/system/HTTP/IncomingRequest.php',
-            __DIR__ . '/system/Security/Security.php',
             __DIR__ . '/system/Session/Session.php',
         ],