fixup! refactor: slim down valuetransformer.h and auto memory management

src/util/valuetransformer.cpp

@@ -93,7 +93,7 @@ double ValueTransformer::transform(double argument) const {
             m_transformers.cend(),
             argument,
             [&](double argument, const auto& pNode) {
-                return pNode->transformInverse(argument);
+                return pNode->transform(argument);
             });
 }
 
@@ -113,6 +113,7 @@ std::unique_ptr<ValueTransformer> ValueTransformer::parseFromXml(
         return nullptr;
     }
 
+    // constructor is private, so we can't use std::make_unique
     auto pTransformer = std::unique_ptr<ValueTransformer>(new ValueTransformer());
 
     auto maybeAddFromElement = [&]<typename T>(auto element) {