Add CryptographicUsageMask filtering support for Locate

This change updates Locate operation support in the PyKMIP server,
allowing users to filter objects based on the object's
Cryptographic Usage Masks. Unit tests and integration tests have
been added to test and verify the correctness of this feature.

Additionally, the Locate demo scripts have also been updated to
support Cryptographic Usage Mask filtering. Simply use the
"--cryptographic-usage-mask" flag to specify one or more
Cryptographic Usage Mask enumeration values for the Locate script
to filter on.

kmip/demos/units/locate.py

@@ -43,6 +43,7 @@ if __name__ == '__main__':
     object_type = opts.object_type
     cryptographic_algorithm = opts.cryptographic_algorithm
     cryptographic_length = opts.cryptographic_length
+    cryptographic_usage_masks = opts.cryptographic_usage_masks
     unique_identifier = opts.unique_identifier
     operation_policy_name = opts.operation_policy_name
 
@@ -174,6 +175,29 @@ if __name__ == '__main__':
             )
             client.close()
             sys.exit(-6)
+    if cryptographic_usage_masks:
+        masks = []
+        for cryptographic_usage_mask in cryptographic_usage_masks:
+            mask = getattr(
+                enums.CryptographicUsageMask,
+                cryptographic_usage_mask,
+                None
+            )
+            if mask:
+                masks.append(mask)
+            else:
+                logger.error(
+                    "Invalid cryptographic usage mask provided: {}".format(
+                        cryptographic_usage_mask
+                    )
+                )
+                sys.exit(-7)
+        attributes.append(
+            attribute_factory.create_attribute(
+                enums.AttributeType.CRYPTOGRAPHIC_USAGE_MASK,
+                masks
+            )
+        )
     if unique_identifier:
         attributes.append(
             attribute_factory.create_attribute(