[Select] add new prop to SelectContent to account for shadow dom rendering

[abrehamgezahegn]

Description

Fix for #2606 .
Select arrow navigation depends on document.activeElement. But if the select is rendered in shadow dom, document.activeElement returns top level element in the shadow dom. This breaks the keyboard navigation.

I edited the keyboard handler to check if select is in shadow dom then get the active element from it.
B