database: Pass master seed to challenge response keys

* Pass the master seed from the database to CompositeKey::challenge()
  function which will in turn issue challenges to all selected
  drivers.

Signed-off-by: Kyle Manna <kyle@kylemanna.com>

src/core/Database.h

@@ -89,6 +89,7 @@ public:
     quint64 transformRounds() const;
     QByteArray transformedMasterKey() const;
     const CompositeKey & key() const;
+    QByteArray challengeMasterSeed(const QByteArray& masterSeed) const;
 
     void setCipher(const Uuid& cipher);
     void setCompressionAlgo(Database::CompressionAlgorithm algo);