Make Derivation of Enumerated Well Items Public

We need this ability to handle segment level UDQ ASSIGN statements
too, so give the operation a well defined home and call it where
applicable.

opm/input/eclipse/Schedule/UDQ/UDQSet.hpp

@@ -29,6 +29,10 @@
 #include <unordered_map>
 #include <vector>
 
+namespace Opm {
+    class SegmentSet;
+} // namespace Opm
+
 namespace Opm {
 
 class UDQScalar
@@ -197,6 +201,9 @@ public:
         }
     };
 
+    static std::vector<EnumeratedWellItems>
+    getSegmentItems(const SegmentSet& segmentSet);
+
     /// Construct empty, named UDQ set of specific variable type
     ///
     /// \param[in] name UDQ set name