Merge #780: Fix: Ensure 'Transaction View' remains disabled if no wallet is selected

b2e531e qt: update widgets availability on wallet selection (pablomartin4btc)

Pull request description:

  This PR addresses an issue where, with no wallet selected, ticking on "Settings -> Mask values" checkbox twice enables the transaction tab when the checkbox is unticked.

  <details>
  <summary>Current behavior display on master</summary>

  ![Peek 2023-12-06 19-18](https://github.com/bitcoin-core/gui/assets/110166421/6ca4eab6-5ef0-44c1-971c-89b8bc7f0283)

  </details>

  <details>
  <summary>Correction display from this branch</summary>

  ![Peek 2023-12-07 13-07](https://github.com/bitcoin-core/gui/assets/110166421/1c78f2aa-1cf7-4d63-b4ce-c034877b4832)

  </details>

  Note for maintaners: this PR should be backported to both 25.x and 26.x.

  ---

  Originally this PR was disabling the "Mask Values" checkbox when no wallet was selected but since a reviewer pointed out that a user might want to open a wallet already on "privacy mode" I rolled that change out.

  <details>
  <summary>Original correction  display disabling "Mask Values" </summary>

  ![Peek 2023-12-06 19-11](https://github.com/bitcoin-core/gui/assets/110166421/66fdf023-998a-434d-a5bd-1a3d848fb751)

  </details>

ACKs for top commit:
  alfonsoromanz:
    Tested ACK b2e531e
  hebasto:
    ACK b2e531e, tested on Ubuntu 22.04.

Tree-SHA512: 6be77ab4d5ec86267a9b0a289a4d8600bb67d279f7e0be65e47b608ec392fe705cf026e32f3c082d2f27449b697d1d9e6a1d110035900d7a804ba823c9f5dfd4

Author: hebasto

src/qt/bitcoingui.cpp

@@ -673,8 +673,10 @@ void BitcoinGUI::setClientModel(ClientModel *_clientModel, interfaces::BlockAndH
 #ifdef ENABLE_WALLET
 void BitcoinGUI::enableHistoryAction(bool privacy)
 {
-    historyAction->setEnabled(!privacy);
-    if (historyAction->isChecked()) gotoOverviewPage();
+    if (walletFrame->currentWalletModel()) {
+        historyAction->setEnabled(!privacy);
+        if (historyAction->isChecked()) gotoOverviewPage();
+    }
 }
 
 void BitcoinGUI::setWalletController(WalletController* wallet_controller, bool show_loading_minimized)