[PD] make pointers to the UI std::unique_ptr

Same as PR #4293, just for PartDesign

as noted in https://github.com/FreeCAD/FreeCAD/pull/4271#discussion_r554673632
the pointer to the UI should be a unique pointer.

This PR does this for all PartDesign dialogs that don't already use a unique_ptr.

src/Mod/PartDesign/Gui/TaskRevolutionParameters.cpp

@@ -58,11 +58,11 @@ using namespace Gui;
 /* TRANSLATOR PartDesignGui::TaskRevolutionParameters */
 
 TaskRevolutionParameters::TaskRevolutionParameters(PartDesignGui::ViewProvider* RevolutionView, QWidget *parent)
-    : TaskSketchBasedParameters(RevolutionView, parent, "PartDesign_Revolution",tr("Revolution parameters"))
+    : TaskSketchBasedParameters(RevolutionView, parent, "PartDesign_Revolution", tr("Revolution parameters"))
+    , ui(new Ui_TaskRevolutionParameters)
 {
     // we need a separate container widget to add all controls to
     proxy = new QWidget(this);
-    ui = new Ui_TaskRevolutionParameters();
     ui->setupUi(proxy);
     QMetaObject::connectSlotsByName(this);
 
@@ -379,8 +379,6 @@ TaskRevolutionParameters::~TaskRevolutionParameters()
         ex.ReportException();
     }
 
-    delete ui;
-
     for (size_t i = 0; i < axesInList.size(); i++) {
         delete axesInList[i];
     }