* Moves the sidebar into the header so that user can tab directly from
the sidebar button into the sidebar (when open).
* Because the sidebar is absolutely positioned inside the header and the
header applies a top-margin, we need to adjust the top position
calculation for the sidebar.
* Removes the checkbox from the accessibility tree through CSS `display:
none;` instead of HTML attributes.
* Given that the checkbox is not able to receive focus, the
`#mw-sidebar-checkbox:focus ~ .mw-header .mw-checkbox-hack-button` CSS
rule is obsolete and moved instead to the label button. An additional
outline: 0 rule was added to remove the dotted outline that Firefox
applies.
* Makes the "Skip to navigation" jump link point to the sidebar now.
After the sidebar has been tabbed through, the rest of the navigation
can be tabbed to.
Bug: T246420
Change-Id: I981da3650854568bb9cfbf3c6c59e7625e7d094c
Add a menu button that toggles the panel's (also referred to as a
sidebar) collapse state. When the screen is wide enough, animate the
transition.
The menu icon from OOUI is copied into Vector to avoid two
ResourceLoaders modules (collapseHorizontal icon isn't ready for
inclusion in the OOUI icon pack and ResourceLoaderOOUIIconPackModule
doesn't support images).
Additional polish and collaboration is needed but this patch fulfills
the scope of its referenced task.
Bug: T246419
Depends-On: I8e153c0ab927f9d880a68fb9efb0bf37b91d26b2
Change-Id: Ic9d54de7e19ef8d5dfd703d95a45b78c0aaf791a
