move the shared TOML helpers into the utility namespace to avoid name collisions

src/lib/config/TomlHelpers.cpp

@@ -3,6 +3,9 @@
 #include <sstream>
 #include <utility>
 
+namespace utility
+{
+
 // --- Error helpers --------------------------------------------------------
 
 std::runtime_error makeError(const std::string& file,
@@ -165,3 +168,5 @@ toml::table parseFile(const std::string& path, const std::string& file)
         throw std::runtime_error(oss.str());
     }
 }
+
+}  // namespace utility