fix: optimization: PVS-Studio warning V832

It's better to use '= default;' syntax instead of empty constructor and destructor body.
Using '= default;' can help the compiler generate more optimal code.

Reported by: PVS-Studio

Signed-off-by: Vyacheslav Ivanov <islavaivanov76@gmail.com>

src/data/dynamic.hpp

@@ -41,7 +41,7 @@ namespace dynamic {
     public:
         std::vector<Value> values;
 
-        List() {}
+        List() = default;
         List(std::vector<Value> values) : values(std::move(values)) {}
 
         std::string str(size_t index) const;
@@ -79,7 +79,7 @@ namespace dynamic {
     public:
         std::unordered_map<std::string, Value> values;
 
-        Map() {}
+        Map() = default;
         Map(std::unordered_map<std::string, Value> values) 
         : values(std::move(values)) {};