fix(Page): Use "open" prop

[aDogCalledSpot]

No description provided.

[ctron]

I am wondering if the page should control this itself? Or maybe just honor the state of the property. Or, add an optional callback, relying on the callback when set, and self-manager otherwise?

[aDogCalledSpot]

The silent overwriting of the prop is definitely a bit strange.

How about using Option<bool> for the PageSidebar.open? Then check for the prop in the Page. If it's Some(b) then use it and if it's None then self-manage.

[ctron]

Would work too. But I guess we would still need a callback for propagate this state.

[aDogCalledSpot]

I'll merge this for now