Fix ugly scrollbars in TabbedView (settings), emojipicker and widgets

[t3chguy]

Fixes element-hq/element-web#12906
Fixes element-hq/element-web#12907
Fixes element-hq/element-web#12910

[bwindels]

actually, need to double check but we might be able to get rid of the autohidescrollbar component completely as it doesn't require js anymore, or does it?

[bwindels]

Thanks for taking a look at this btw. So yeah, we could apply the behaviour to any scrolling area by applying the css class (mx_AutoHideScrollbar). I wonder if we should rename it for that purpose though?

[t3chguy]

Yeah, we could apply the behaviour to any scrolling area by applying the css class (mx_AutoHideScrollbar). I wonder if we should rename it for that purpose though?

Yes but I think maybe we should just apply it globally to all scrollbars, very few scrollbars are always-visible and where they are it seems inconsistent.

[bwindels]

So, as discussed in the standup, we keep the component to isolate the css class. So we just merge this and then I have a look why code blocks reverted to ugly scrollbars?

[t3chguy]

sgtm

[bwindels]

oops, forgot to approve.