[MeL] Implement function getBulkIDString()

Using the function avoids the distribution of the magic names 'bulk_node_ids',
'bulk_element_ids', and 'bulk_face_ids' to several places in OGS.

MeshLib/Properties.cpp

@@ -174,4 +174,34 @@ std::map<std::string, PropertyVectorBase*>::size_type Properties::size(
                     [&](auto const p)
                     { return p.second->getMeshItemType() == mesh_item_type; });
 }
+
+std::string getBulkIDString(MeshItemType mesh_item_type)
+{
+    switch (mesh_item_type)
+    {
+        case MeshItemType::Node:
+            return "bulk_node_ids";
+            break;
+        case MeshItemType::Cell:
+            return "bulk_element_ids";
+            break;
+        case MeshItemType::Edge:
+            return "bulk_edge_ids";
+            break;
+        case MeshItemType::Face:
+            return "bulk_face_ids";
+            break;
+        case MeshItemType::IntegrationPoint:
+            OGS_FATAL("MeshItemType::IntegrationPoint is not handled.");
+            return "";
+            break;
+        default:
+            OGS_FATAL(
+                "Unknown mesh item type. At the moment only for mesh item "
+                "types 'Node', 'Cell', and 'Face' mapping names are "
+                "specified.");
+            return "";
+    }
+}
+
 }  // end namespace MeshLib

MeshLib/Properties.h

@@ -173,6 +173,12 @@ private:
 template <typename Function>
 void applyToPropertyVectors(Properties const& properties, Function f);
 
+/// Returns the mapping MeshItemType -> bulk ID property name, i.e.
+/// MeshItemType::Node -> bulk_node_ids
+/// MeshItemType::Cell -> bulk_element_ids
+/// MeshItemType::Face -> bulk_face_ids
+std::string getBulkIDString(MeshItemType mesh_item_type);
+
 #include "Properties-impl.h"
 
 } // end namespace MeshLib