[PD] add shortcut to context menus

- people should be informed that there is a shortcut available (that was recently added)
- make the shortcut also translatable since "Del" means nothing in e.g. German
- minor code style fix in TaskDressUpParameters.h

src/Mod/PartDesign/Gui/TaskLinearPatternParameters.cpp

@@ -113,7 +113,11 @@ void TaskLinearPatternParameters::setupUI()
 
     // Create context menu
     QAction* action = new QAction(tr("Remove"), this);
-    action->setShortcut(QString::fromLatin1("Del"));
+    action->setShortcut(tr("Del"));
+#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
+    // display shortcut behind the context menu entry
+    action->setShortcutVisibleInContextMenu(true);
+#endif
     ui->listWidgetFeatures->addAction(action);
     connect(action, SIGNAL(triggered()), this, SLOT(onFeatureDeleted()));
     ui->listWidgetFeatures->setContextMenuPolicy(Qt::ActionsContextMenu);