Add toolbar

[khang-nd]

Design guideline: https://learn.microsoft.com/en-us/windows/win32/uxguide/cmd-toolbars

This could be a great addition to this framework as Toolbar appears to be a common component to have in most designs.

A past effort to implement this can be referenced in #114.

[kyr0]

I would backport it to XP.css as I need this in my XP retro project :)