[PD] fix property issues

- Helix: the property Turns has the App::PropertyFloatConstraint thus also the pointer to it must have the same property

- LinearPattern and Helix: make constraints static class member (forgot this in commit 114bdf6b)

- Draft: make the constraint const

- PolarPattern and LinearPattern assure that the header file is loaded at last to avoid potential troubles

src/Mod/PartDesign/App/FeatureDraft.cpp

@@ -67,7 +67,7 @@ using namespace PartDesign;
 
 PROPERTY_SOURCE(PartDesign::Draft, PartDesign::DressUp)
 
-App::PropertyAngle::Constraints Draft::floatAngle = { 0.0, 90.0 - Base::toDegrees<double>(Precision::Angular()), 0.1 };
+const App::PropertyAngle::Constraints Draft::floatAngle = { 0.0, 90.0 - Base::toDegrees<double>(Precision::Angular()), 0.1 };
 
 Draft::Draft()
 {