Function json_pointer

include/behaviortree_cpp/contrib/json.hpp:13867–13869

@brief create JSON pointer @sa https://json.nlohmann.me/api/json_pointer/json_pointer/

    /// @brief create JSON pointer
    /// @sa https://json.nlohmann.me/api/json_pointer/json_pointer/
    explicit json_pointer(const string_t& s = "")
        : reference_tokens(split(s))
    {}

    /// @brief return a string representation of the JSON pointer
    /// @sa https://json.nlohmann.me/api/json_pointer/to_string/