[TechDraw]Detail highlight drag (fix #21828) (#22036)

* [TD]add preferences for detail highlight snapping

* [TD]fix highlight drag issues

* Update src/Mod/TechDraw/Gui/TaskDetail.cpp

minor format change from benj5378.

Co-authored-by: Benjamin Bræstrup Sayoc <benj5378@outlook.com>

---------

Co-authored-by: Benjamin Bræstrup Sayoc <benj5378@outlook.com>

src/Mod/TechDraw/App/DrawViewPart.h

@@ -243,6 +243,9 @@ public:
     bool isCosmeticEdge(const std::string& element);
     bool isCenterLine(const std::string& element);
 
+    Base::Vector3d snapHighlightToVertex(Base::Vector3d newAnchorPoint, double radius) const;
+
+
 public Q_SLOTS:
     void onHlrFinished(void);
     void onFacesFinished(void);