Improve well path modeling

* Improve handling of MD at first target
* When sea level well target is disabled, update MD of first target
* Show well target spheres by default, allow toggling of spheres
* Activate well target modifiers when clicking on well targets
* Remove selection update causing an unstable 3D view
* Improve display and handling of multiple locations
* Add special 3D target for tie in well target
* Add slider to tie in MD input field
* Show MD in well path target table
* Delete all well path laterals when deleting a well path

* Python : Add lateral to parent well
* Python : Add perforation interval

ApplicationLibCode/ProjectDataModel/WellPath/RimWellPath.h

@@ -163,6 +163,7 @@ public:
     RimWellPath*              topLevelWellPath();
     const RimWellPath*        topLevelWellPath() const;
     std::vector<RimWellPath*> allWellPathLaterals() const;
+    std::vector<RimWellPath*> wellPathLaterals() const;
 
     RimWellPathTieIn* wellPathTieIn() const;
     void              connectWellPaths( RimWellPath* childWell, double tieInMeasuredDepth );