Add `attributes` on `StepOptionsButton`

Hello !
I would like to be able to add a data-testid attribute on the generated buttons for the tour, in order to ease the E2E tests of my application.
My code would look like

        const steps: Step.StepOptions[] = [
            {
                id: TourService.STEP_0_WELCOME,
                text: `<h1>Welcome !</h1>
                        <div>Let us take you on a quick tour.</div>`,
                buttons: [
                    {
                        classes: 'tour-button-secondary',
                        text: 'Skip tutorial',
                        attributes: {'data-testid', 'tutorial-button-skip'},
                        action: skip,
                    },
                    {
                        classes: 'tour-button-primary',
                        text: 'Next',
                        attributes: {'data-testid', 'tutorial-button-next'},
                        action: next,
                    },
                ],
            },
         }

Do you think this is a feature you could add ?

首先定位 StepOptionsButton 入口点，并跟踪 tour 按钮的生成方式。确认请求的 attributes 选项应如何表示，然后确认步骤中提供的 data-testid 会出现在生成的按钮上，并且现有按钮行为保持不变。