Add payload base classes to prepare for simplifying the client

This change adds payload request and response base classes to
prepare for future simplification updates to the current client
architecture. No new tests are required for this change.

kmip/core/messages/payloads/destroy.py

@@ -16,18 +16,16 @@
 from kmip.core import attributes
 from kmip.core import enums
 from kmip.core.enums import Tags
-
-from kmip.core.primitives import Struct
-
+from kmip.core.messages.payloads import base
 from kmip.core.utils import BytearrayStream
 
 
 # 4.21
-class DestroyRequestPayload(Struct):
+class DestroyRequestPayload(base.RequestPayload):
 
     def __init__(self,
                  unique_identifier=None):
-        super(DestroyRequestPayload, self).__init__(enums.Tags.REQUEST_PAYLOAD)
+        super(DestroyRequestPayload, self).__init__()
         self.unique_identifier = unique_identifier
         self.validate()
 
@@ -67,12 +65,11 @@ class DestroyRequestPayload(Struct):
         pass
 
 
-class DestroyResponsePayload(Struct):
+class DestroyResponsePayload(base.ResponsePayload):
 
     def __init__(self,
                  unique_identifier=None):
-        super(DestroyResponsePayload, self).__init__(
-            enums.Tags.RESPONSE_PAYLOAD)
+        super(DestroyResponsePayload, self).__init__()
         self.unique_identifier = unique_identifier
         self.validate()