Add to/fromAron() for one-sided optional and test utilities for C++/Python conversion

• ARON conversions (C++): Add overloads for one-sided optional
• Add test utilities for testing C++ to Python conversion of ARON classes

Related to:

• python3-armarx!33 (merged)
• https://git.h2t.iar.kit.edu/sw/armarx/speechx/-/merge_requests/17

source/RobotAPI/libraries/aron/core/aron_conversions.h

@@ -139,6 +139,22 @@ namespace armarx::aron
         }
     }
 
+
+    // One-sided optional
+    template <class DtoT, class BoT>
+    void toAron(std::optional<DtoT>& dto, const BoT& bo)
+    {
+        dto = DtoT{};
+        toAron(*dto, bo);
+    }
+    template <class DtoT, class BoT>
+    void fromAron(DtoT& dto, const std::optional<BoT>& bo)
+    {
+        bo = BoT{};
+        fromAron(dto, *bo);
+    }
+
+
     // Flag-controlled optional
     template <class DtoT, class BoT>
     void toAron(DtoT& dto, bool& dtoValid, const BoT& bo, bool boValid)
@@ -154,6 +170,7 @@ namespace armarx::aron
         }
     }
 
+
     template <class DtoT, class BoT>
     void fromAron(const DtoT& dto, bool dtoValid, BoT& bo, bool& boValid)
     {