small changes in log_manager.cpp and add is_database_primitive type traits and test

include/matador/utils/types.hpp

@@ -46,6 +46,23 @@ struct time_type_t {
   uint32_t microsecond{};
 };
 
+namespace detail {
+template <typename T, typename Variant>
+struct is_in_variant;
+
+template <typename T, typename... Alts>
+struct is_in_variant<T, std::variant<Alts...>>
+  : std::bool_constant<(std::is_same_v<T, Alts> || ...)> {
+};
+}
+
+template<typename T>
+struct is_database_primitive : detail::is_in_variant<std::remove_cv_t<std::remove_reference_t<T>>, database_type> {
+};
+
+template <typename T>
+inline constexpr bool is_database_primitive_v = is_database_primitive<T>::value;
+
 void initialize_by_basic_type(basic_type type, database_type &val);