dictGet('name', ...) should check for XML dictionary 'name' if XML dict=name does not exists then use SQL dictionary from the currectDatabase()

{
public:
    static constexpr auto name = "dictGetHierarchy";
    static FunctionPtr create(const Context & context)
    {
        return std::make_shared<FunctionDictGetHierarchy>(context);
    }
    explicit FunctionDictGetHierarchy(const Context & context_) : helper(context_) {}
    String getName() const override { return name; }
private:
    size_t getNumberOfArguments() const override { return 2; }
    bool isInjective(const ColumnsWithTypeAndName & ) const override { return true; }
    bool useDefaultImplementationForConstants() const final { return true; }
    ColumnNumbers getArgumentsThatAreAlwaysConstant() const final { return {0}; }
    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
    {
        if (!isString(arguments[0]))
            throw Exception{"Illegal type " + arguments[0]->getName() + " of first argument of function " + getName()
                + ", expected a string.", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT};
        if (!WhichDataType(arguments[1]).isUInt64())
            throw Exception{"Illegal type " + arguments[1]->getName() + " of second argument of function " + getName()
                + ", must be UInt64.", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT};
        return std::make_shared<DataTypeArray>(std::make_shared<DataTypeUInt64>());
    }
    bool isDeterministic() const override { return false; }
    ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, size_t input_rows_count) const override