Remove use of uiInterface.LoadWallet in wallet code

This also changes the uiInterface.LoadWallet signal argument type from
shared_ptr<CWallet> to unique_ptr<interfaces::Wallet> because CWallet is an
internal wallet class that shouldn't be used in non-wallet code (and also can't
be passed across process boundaries).

This commit does not change behavior.

src/interfaces/chain.cpp

@@ -6,6 +6,7 @@
 
 #include <chain.h>
 #include <chainparams.h>
+#include <interfaces/wallet.h>
 #include <net.h>
 #include <policy/fees.h>
 #include <policy/policy.h>
@@ -251,6 +252,7 @@ public:
     void initMessage(const std::string& message) override { ::uiInterface.InitMessage(message); }
     void initWarning(const std::string& message) override { InitWarning(message); }
     void initError(const std::string& message) override { InitError(message); }
+    void loadWallet(std::unique_ptr<Wallet> wallet) override { ::uiInterface.LoadWallet(wallet); }
 };
 
 } // namespace

src/interfaces/chain.h

@@ -24,6 +24,8 @@ struct FeeCalculation;
 
 namespace interfaces {
 
+class Wallet;
+
 //! Interface for giving wallet processes access to blockchain state.
 class Chain
 {
@@ -187,6 +189,9 @@ public:
 
     //! Send init error.
     virtual void initError(const std::string& message) = 0;
+
+    //! Send wallet load notification to the GUI.
+    virtual void loadWallet(std::unique_ptr<Wallet> wallet) = 0;
 };
 
 //! Interface to let node manage chain clients (wallets, or maybe tools for

src/interfaces/node.cpp

@@ -275,7 +275,7 @@ public:
     }
     std::unique_ptr<Handler> handleLoadWallet(LoadWalletFn fn) override
     {
-        return MakeHandler(::uiInterface.LoadWallet_connect([fn](std::shared_ptr<CWallet> wallet) { fn(MakeWallet(wallet)); }));
+        return MakeHandler(::uiInterface.LoadWallet_connect([fn](std::unique_ptr<Wallet>& wallet) { fn(std::move(wallet)); }));
     }
     std::unique_ptr<Handler> handleNotifyNumConnectionsChanged(NotifyNumConnectionsChangedFn fn) override
     {