Type letter to focus menu item for ASelect

[frattaro]

Is your feature request related to a problem? Please describe.

Native selects have a feature where you can type a letter and it automatically focuses that menu-list item. That should be added to get parity if not for the obvious UX improvement.

Describe the solution you'd like

When the select surface or menu is focused, catch Key...Down? events, check to see if it's a letter, and then focus to the first element that has that.

For bonus points, store the typed keys and zoom to the first entry starting with a sequence of keys. Debounce clearing that state after 1? 2? seconds.