ProjectExplorer: Make BuildStepConfigWidget::displayName a value

Use BuildStep::displayName() as default.

This probably could be the only possibility, but currently there
are some discrepancies that are kept in this patch to make
the patch mechanical.

Change-Id: I2a1e5c2ff37ad95e25309eb16e07099e42191f60
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/ios/iosdeploystepwidget.cpp

@@ -39,6 +39,7 @@ IosDeployStepWidget::IosDeployStepWidget(IosDeployStep *step) :
     ui(new Ui::IosDeployStepWidget),
     m_step(step)
 {
+    setDisplayName(QString::fromLatin1("<b>%1</b>").arg(m_step->displayName()));
     ui->setupUi(this);
     connect(m_step, &ProjectExplorer::ProjectConfiguration::displayNameChanged,
             this, &ProjectExplorer::BuildStepConfigWidget::updateSummary);
@@ -49,11 +50,6 @@ IosDeployStepWidget::~IosDeployStepWidget()
     delete ui;
 }
 
-QString IosDeployStepWidget::displayName() const
-{
-    return QString::fromLatin1("<b>%1</b>").arg(m_step->displayName());
-}
-
 QString IosDeployStepWidget::summaryText() const
 {
     return displayName();