wallet_api: add seed_offset param to seed()

src/wallet/api/wallet.cpp

@@ -791,11 +791,11 @@ bool WalletImpl::close(bool store)
     return result;
 }
 
-std::string WalletImpl::seed() const
+std::string WalletImpl::seed(const std::string& seed_offset) const
 {
     epee::wipeable_string seed;
     if (m_wallet)
-        m_wallet->get_seed(seed);
+        m_wallet->get_seed(seed, seed_offset);
     return std::string(seed.data(), seed.size()); // TODO
 }
 

src/wallet/api/wallet.h

@@ -81,7 +81,7 @@ public:
                            const std::string &device_name);
     Device getDeviceType() const override;
     bool close(bool store = true);
-    std::string seed() const override;
+    std::string seed(const std::string& seed_offset = "") const override;
     std::string getSeedLanguage() const override;
     void setSeedLanguage(const std::string &arg) override;
     // void setListener(Listener *) {}

src/wallet/api/wallet2_api.h

@@ -446,7 +446,7 @@ struct Wallet
     };
 
     virtual ~Wallet() = 0;
-    virtual std::string seed() const = 0;
+    virtual std::string seed(const std::string& seed_offset = "") const = 0;
     virtual std::string getSeedLanguage() const = 0;
     virtual void setSeedLanguage(const std::string &arg) = 0;
     //! returns wallet status (Status_Ok | Status_Error)