Publish Short Region Set Names Only

That way, in-place quantities will go through the short-to-canonical
name translation in FieldProps regardless of their origin--e.g.,
RPTSOL/RPTSCHED or explicit SUMMARY section vectors.

opm/simulators/utils/ParallelEclipseState.cpp

@@ -228,10 +228,12 @@ bool ParallelFieldPropsManager::has_double(const std::string& keyword) const
 
 std::vector<std::string> ParallelFieldPropsManager::fip_regions() const
 {
+    constexpr auto maxchar = std::string::size_type{6};
+
     std::vector<std::string> result;
     for (const auto& key : m_intProps) {
         if (Fieldprops::keywords::isFipxxx(key.first)) {
-            result.push_back(key.first);
+            result.push_back(key.first.substr(0, maxchar));
         }
     }
     return result;