expose set_offline to wallet api

src/wallet/api/wallet.cpp

@@ -2305,6 +2305,10 @@ bool WalletImpl::rescanSpent()
   return true;
 }
 
+void WalletImpl::setOffline(bool offline)
+{
+    m_wallet->set_offline(offline);
+}
 
 void WalletImpl::hardForkInfo(uint8_t &version, uint64_t &earliest_height) const
 {

src/wallet/api/wallet.h

@@ -181,6 +181,8 @@ public:
     virtual bool setCacheAttribute(const std::string &key, const std::string &val) override;
     virtual std::string getCacheAttribute(const std::string &key) const override;
 
+    virtual void setOffline(bool offline) override;
+
     virtual bool setUserNote(const std::string &txid, const std::string &note) override;
     virtual std::string getUserNote(const std::string &txid) const override;
     virtual std::string getTxKey(const std::string &txid) const override;

src/wallet/api/wallet2_api.h

@@ -1007,6 +1007,12 @@ struct Wallet
     * \return true on success
     */
     virtual bool rescanSpent() = 0;
+
+   /*
+    * \brief setOffline - toggle set offline on/off
+    * \param offline - true/false
+    */
+    virtual void setOffline(bool offline) = 0;
     
     //! blackballs a set of outputs
     virtual bool blackballOutputs(const std::vector<std::string> &outputs, bool add) = 0;