Fix type incompatibility

Use __bytes__ instead of __string__ to make GUID compatible with bytes()

Author: bihanssen

nordicsemi/lister/windows/structures.py

@@ -123,6 +123,8 @@ def __init__(self, bytes):
         self._internal = bytes
     def __str__(self):
         return self._internal.raw
+    def __bytes__(self):
+        return self._internal.raw
 
 DeviceInfoData.size = DeviceInfoData.cbSize
 DeviceInfoData.dev_inst = DeviceInfoData.DevInst