Python adjustments (#7809)

* #7797 Well Targets: Add scripting capability
* #7794 Python : Do not update childField or childFieldArray
* #7797: Python - Add scripting to well path collection
- Extend the pdmobject.py with method add_object()
- allow objects to be created from Python in well path collections
- add well targets to modelled well path

* #7795 Python : Make sure referenced generated classes are defined
* #7810 StimPlanModel: clean-up python generation
* Python : Always use empty string as default value for ptrFieldValue
It can happen that a ptrField is assigned to a pointer on object construction. (FaciesProperties) Make sure that constructor always assigns an empty string.

Co-authored-by: magnesj <magnesj@users.noreply.github.com>
Co-authored-by: Kristian Bendiksen <kristian.bendiksen@gmail.com>

ApplicationLibCode/ProjectDataModel/RimGridStatisticsPlotCollection.cpp

@@ -30,9 +30,9 @@ CAF_PDM_SOURCE_INIT( RimGridStatisticsPlotCollection, "GridStatisticsPlotCollect
 //--------------------------------------------------------------------------------------------------
 RimGridStatisticsPlotCollection::RimGridStatisticsPlotCollection()
 {
-    CAF_PDM_InitScriptableObject( "Grid Statistics Plots", ":/WellLogPlots16x16.png", "", "" );
+    CAF_PDM_InitObject( "Grid Statistics Plots", ":/WellLogPlots16x16.png", "", "" );
 
-    CAF_PDM_InitScriptableFieldNoDefault( &m_gridStatisticsPlots, "GridStatisticsPlots", "", "", "", "" );
+    CAF_PDM_InitFieldNoDefault( &m_gridStatisticsPlots, "GridStatisticsPlots", "", "", "", "" );
     m_gridStatisticsPlots.uiCapability()->setUiHidden( true );
 }