Twenty Seventeen: active submenu toggle button initial state should have aria expanded true

[afercia]

In Twenty Seventeen, when in the responsive view and when the current menu item is a subitem, the menu shows the active tree expanded. By the way, the submenu toggle button has a wrong initial state. When setting the initial state, 'aria-expanded="true"` should be set together with the CSS class 'toggled-on'.

See in the screenshot below: the current page is "Page Markup And Formatting", the tree it belongs to is expanded, the related toggle button has the proper icon but the wrong aria-expanded value:

[afercia]

P.S. the screen reader text should have the correct text too, in this case it should be Collapse child menu.

[laurelfulford]

39026.patch​ only addressed the aria-expanded issue - 39026.1.patch​ should set the aria-expanded attribute to the correct state, as well as update the button screen reader text in cases where the current menu item is a subitem.

[davidakennedy]

Nice catch @afercia – thank you! I tested 39026.1.patch​ from @laurelfulford and it works well. This should be good to go.

[afercia]

Thanks @laurelfulford and @davidakennedy I'd just suggest to don't get again .current-menu-ancestor > button and make it in one go. The refreshed patch still needs an additional find() but it's a bit more concise.

[davidakennedy]

Noted in #39029, I'd rather go with the patch there from @afercia instead of this one. That patch would also fix the issue here in a similar way.

[helen]

In 39451:

Twenty Seventeen: Improve ARIA for the nav menu.

The onResizeARIA() function was not very useful and buggy.

props afercia.
fixes #39029, #39026.

[helen]

In 39452:

Twenty Seventeen: Improve ARIA for the nav menu.

The onResizeARIA() function was not very useful and buggy.

props afercia.
fixes #39029, #39026 for the 4.7 branch.