feat: add support for request headers

Author: mychidarko

src/Headers.php

@@ -45,6 +45,10 @@ public static function resetStatus($httpCode = 200)
      */
     public static function all(bool $safeOutput = false): array
     {
+        if (class_exists('Leaf\Eien\Server') && PHP_SAPI === 'cli') {
+            return \Leaf\Config::get('request.headers');
+        }
+
         return ($safeOutput === false) ?
             self::findHeaders() :
             \Leaf\Anchor::sanitize(self::findHeaders());