Restricted to the feature flag (?vectorvisualenhancementnext=1)
for now to allow us to not worry about caching.
mw-ui-icon-flush-left and mw-ui-icon-flush-right have been in core
for some time and using them means we don't have to manage hardcoded
values for these.
We'll need to think of .mixin-vector-flush-left-left
and .mixin-vector-flush-right-margin-left separately - I wonder
if these could be revised to use these 2 standard classes.
Additional changes:
- Drop unused mixin-vector-flush-right-margin-left mixin
Bug: T321504
Bug: T317583
Change-Id: I51f8e31be6771a3fb32fb07dc22d0c2872b5706d
Visual changes:
- TOC icon in sticky header
- Small update to the narrow screens collapsed TOC spacing when open
Bug: T311103
Depends-on: Ic94fda79bd14856ccda14985d5860aa54d3118d0
Change-Id: I977092f951ba2843816609e706bce4b99583f623