Treat CDataStream bytes as uint8_t

Also, rename CSerializeData to SerializeData

src/support/allocators/zeroafterfree.h

@@ -42,7 +42,7 @@ struct zero_after_free_allocator : public std::allocator<T> {
     }
 };
 
-// Byte-vector that clears its contents before deletion.
-typedef std::vector<char, zero_after_free_allocator<char> > CSerializeData;
+/** Byte-vector that clears its contents before deletion. */
+using SerializeData = std::vector<uint8_t, zero_after_free_allocator<uint8_t>>;
 
 #endif // BITCOIN_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H