Current situation
When I use my keyboard to move down the list of namespaces, the list does not scroll. I can still select all namespacase, but when they are outside of the current view, I have to do so blindly, and get confusing UI indications (which pretends the first namespace is selected)

Task
Let the namespace list scroll in a way, that the focus is always in view (Like in recent changes for reference)

Acceptance criteria

• When using the keyboard arrows to navigate through the namespace list, I can reach all items in that list to select them.
• I can move up and down the entire list.

Notes

• Maybe @Mooeypoo or @Catrope can help, this is really unclear to us why it is behaving this way
• This seems to be related to competing OOUI events. MediaWiki-Recent-changes seems to have similar problems, but wrote their own scrolling mechanism, which is an overkill for our code base