wallet2_api: implement stop() to interrupt refresh() loop once

src/wallet/api/wallet.cpp

@@ -910,6 +910,11 @@ std::string WalletImpl::path() const
     return m_wallet->path();
 }
 
+void WalletImpl::stop()
+{
+    m_wallet->stop();
+}
+
 bool WalletImpl::store(const std::string &path)
 {
     clearStatus();

src/wallet/api/wallet.h

@@ -99,6 +99,7 @@ public:
     std::string publicSpendKey() const override;
     std::string publicMultisigSignerKey() const override;
     std::string path() const override;
+    void stop() override;
     bool store(const std::string &path) override;
     std::string filename() const override;
     std::string keysFilename() const override;

src/wallet/api/wallet2_api.h

@@ -507,6 +507,11 @@ struct Wallet
      */
     virtual std::string publicMultisigSignerKey() const = 0;
 
+    /*!
+     * \brief stop - interrupts wallet refresh() loop once (doesn't stop background refresh thread)
+     */
+    virtual void stop() = 0;
+
     /*!
      * \brief store - stores wallet to file.
      * \param path - main filename to store wallet to. additionally stores address file and keys file.