DT1 widget: subtitle type scrollbar should be a drop-down

[gravestench]

This scrollbar would make a lot more sense as a drop-down.

[bbrucee]

This should be straightforward to implement based off of the dropdown menu in the DC6 widget: https://github.com/OpenDiablo2/HellSpawner/blob/master/hswidget/dc6widget/widget.go#L148

[bbrucee]

[bbrucee]

WIP: width of the dropdown up for discussion