scripted-diff: Remove unused "What's This" button in dialogs on Windows

-BEGIN VERIFY SCRIPT-
git grep -l 'QDialog(parent)' -- src/qt | xargs sed -i -E 's/QDialog\(parent\)/QDialog\(parent, GUIUtil::dialog_flags\)/g'
patch -p1 << "EOF"
--- a/src/qt/guiutil.h
+++ b/src/qt/guiutil.h
@@ -43,6 +43,9 @@ QT_END_NAMESPACE
  */
 namespace GUIUtil
 {
+    // Use this flags to prevent a "What's This" button in the title bar of the dialog on Windows.
+    constexpr auto dialog_flags = Qt::WindowTitleHint | Qt::WindowSystemMenuHint | Qt::WindowCloseButtonHint;
+
     // Create human-readable string from date
     QString dateTimeStr(const QDateTime &datetime);
     QString dateTimeStr(qint64 nTime);
--- a/src/qt/createwalletdialog.cpp
+++ b/src/qt/createwalletdialog.cpp
@@ -9,6 +9,8 @@
 #include <qt/createwalletdialog.h>
 #include <qt/forms/ui_createwalletdialog.h>

+#include <qt/guiutil.h>
+
 #include <QPushButton>

 CreateWalletDialog::CreateWalletDialog(QWidget* parent) :
EOF
-END VERIFY SCRIPT-

Author: hebasto

src/qt/addressbookpage.cpp

@@ -56,7 +56,7 @@ class AddressBookSortFilterProxyModel final : public QSortFilterProxyModel
 };
 
 AddressBookPage::AddressBookPage(const PlatformStyle *platformStyle, Mode _mode, Tabs _tab, QWidget *parent) :
-    QDialog(parent),
+    QDialog(parent, GUIUtil::dialog_flags),
     ui(new Ui::AddressBookPage),
     model(nullptr),
     mode(_mode),

src/qt/askpassphrasedialog.cpp

@@ -20,7 +20,7 @@
 #include <QPushButton>
 
 AskPassphraseDialog::AskPassphraseDialog(Mode _mode, QWidget *parent, SecureString* passphrase_out) :
-    QDialog(parent),
+    QDialog(parent, GUIUtil::dialog_flags),
     ui(new Ui::AskPassphraseDialog),
     mode(_mode),
     model(nullptr),

src/qt/coincontroldialog.cpp

@@ -42,7 +42,7 @@ bool CCoinControlWidgetItem::operator<(const QTreeWidgetItem &other) const {
 }
 
 CoinControlDialog::CoinControlDialog(CCoinControl& coin_control, WalletModel* _model, const PlatformStyle *_platformStyle, QWidget *parent) :
-    QDialog(parent),
+    QDialog(parent, GUIUtil::dialog_flags),
     ui(new Ui::CoinControlDialog),
     m_coin_control(coin_control),
     model(_model),

src/qt/createwalletdialog.cpp

@@ -9,10 +9,12 @@
 #include <qt/createwalletdialog.h>
 #include <qt/forms/ui_createwalletdialog.h>
 
+#include <qt/guiutil.h>
+
 #include <QPushButton>
 
 CreateWalletDialog::CreateWalletDialog(QWidget* parent) :
-    QDialog(parent),
+    QDialog(parent, GUIUtil::dialog_flags),
     ui(new Ui::CreateWalletDialog)
 {
     ui->setupUi(this);

src/qt/editaddressdialog.cpp

@@ -13,7 +13,7 @@
 
 
 EditAddressDialog::EditAddressDialog(Mode _mode, QWidget *parent) :
-    QDialog(parent),
+    QDialog(parent, GUIUtil::dialog_flags),
     ui(new Ui::EditAddressDialog),
     mapper(nullptr),
     mode(_mode),

src/qt/guiutil.h

@@ -43,6 +43,9 @@ QT_END_NAMESPACE
  */
 namespace GUIUtil
 {
+    // Use this flags to prevent a "What's This" button in the title bar of the dialog on Windows.
+    constexpr auto dialog_flags = Qt::WindowTitleHint | Qt::WindowSystemMenuHint | Qt::WindowCloseButtonHint;
+
     // Create human-readable string from date
     QString dateTimeStr(const QDateTime &datetime);
     QString dateTimeStr(qint64 nTime);

src/qt/intro.cpp

@@ -119,7 +119,7 @@ int GetPruneTargetGB()
 } // namespace
 
 Intro::Intro(QWidget *parent, int64_t blockchain_size_gb, int64_t chain_state_size_gb) :
-    QDialog(parent),
+    QDialog(parent, GUIUtil::dialog_flags),
     ui(new Ui::Intro),
     thread(nullptr),
     signalled(false),

src/qt/openuridialog.cpp

@@ -11,7 +11,7 @@
 #include <QUrl>
 
 OpenURIDialog::OpenURIDialog(QWidget *parent) :
-    QDialog(parent),
+    QDialog(parent, GUIUtil::dialog_flags),
     ui(new Ui::OpenURIDialog)
 {
     ui->setupUi(this);

src/qt/optionsdialog.cpp

@@ -28,7 +28,7 @@
 #include <QTimer>
 
 OptionsDialog::OptionsDialog(QWidget *parent, bool enableWallet) :
-    QDialog(parent),
+    QDialog(parent, GUIUtil::dialog_flags),
     ui(new Ui::OptionsDialog),
     model(nullptr),
     mapper(nullptr)

src/qt/psbtoperationsdialog.cpp

@@ -19,7 +19,7 @@
 
 
 PSBTOperationsDialog::PSBTOperationsDialog(
-    QWidget* parent, WalletModel* wallet_model, ClientModel* client_model) : QDialog(parent),
+    QWidget* parent, WalletModel* wallet_model, ClientModel* client_model) : QDialog(parent, GUIUtil::dialog_flags),
                                                                              m_ui(new Ui::PSBTOperationsDialog),
                                                                              m_wallet_model(wallet_model),
                                                                              m_client_model(client_model)