[Feature]: Add ScrollBar Button

[MangMax]

Describe the feature

I tried to add a separate scroll button to mimic the winui style, like this

but ran into a few Problems, due to the space squeeze of the button the scrollbar is positioned outside of my expectations, it seems this can only be solved perfectly by adding the size of the button when calculating the offset, or I'd like to know what options are available to achieve this

Additional information

• I intend to submit a PR for this feature.
• I have already implemented and/or tested this feature.