Merge bitcoin/bitcoin#24313: Improve display address handling for external signer

4357158c47 wallet: return and display signer error (Sjors Provoost)
dc55531087 wallet: compare address returned by displayaddress (Sjors Provoost)
6c1a2cc09a test: use h marker for external signer mock (Sjors Provoost)

Pull request description:

  * HWI returns the requested address: as a sanity check, we now compare that to what we expected
     * external signer documentation now reflects that HWI alternatives must implement this check
  * both RPC and GUI will now return an error text, rather than just fail (the GUI even failed silently in some cases)

ACKs for top commit:
  brunoerg:
    ACK 4357158c47
  achow101:
    ACK 4357158c47

Tree-SHA512: 4f56edf3846745c8e7d08ef55cf29e8bb468256457149377c5f02da097931f9ca0c06bdbd856dc2385cde4fd11e4dc3b634c5a48814ff27f5562c8a25d43da93

src/qt/walletmodel.cpp

@@ -569,16 +569,17 @@ bool WalletModel::bumpFee(uint256 hash, uint256& new_hash)
     return true;
 }
 
-bool WalletModel::displayAddress(std::string sAddress) const
+void WalletModel::displayAddress(std::string sAddress) const
 {
     CTxDestination dest = DecodeDestination(sAddress);
-    bool res = false;
     try {
-        res = m_wallet->displayAddress(dest);
+        util::Result<void> result = m_wallet->displayAddress(dest);
+        if (!result) {
+            QMessageBox::warning(nullptr, tr("Signer error"), QString::fromStdString(util::ErrorString(result).translated));
+        }
     } catch (const std::runtime_error& e) {
         QMessageBox::critical(nullptr, tr("Can't display address"), e.what());
     }
-    return res;
 }
 
 bool WalletModel::isWalletEnabled()

src/qt/walletmodel.h

@@ -130,7 +130,7 @@ public:
     UnlockContext requestUnlock();
 
     bool bumpFee(uint256 hash, uint256& new_hash);
-    bool displayAddress(std::string sAddress) const;
+    void displayAddress(std::string sAddress) const;
 
     static bool isWalletEnabled();