Selector a11y behavior

[travor20814]

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

Seletor a11y

Describe the solution you'd like

When user can only use keyboard to interact with selector, they will use ArrowUp, ArrowDown to select the menu. (And that is the default behavior of the original ). I suggested that do not change the focus on the selector trigger, we staying focus on it, but changing menu activeIndex by listen on keydown event, when user clicked Enter, we apply the activeIndex to the current value.