[Menu] openOnHover issues

[atomiks]

For Menu openOnHover demo

1. First item incorrectly highlighted when mixing pointer/keyboard use

• Focus trigger using keyboard
• Press esc
• Hover the trigger with pointer
• First item highlighted incorrectly (nothing should be highlighted when using pointer)

2. Returns focus and scrolls to element out of view

• Focus 'Group Labels' demo trigger (View) at the bottom with keyboard
• Scroll up and hover the openOnHover demo
• Mouseout of the trigger
• Browser focuses and scrolls down to the 'Group Labels' trigger (focus management should be disabled like Popover when using openOnHover)

3. Stick behavior

• Hover openOnHover demo Menu
• Click
• Mouseout of trigger
• Stays stuck but should not (it also shouldn't stick if you moused into the popup, but didn't click anything)

Side note: I think Popover's implementation can also be improved in that clicking within the patient threshold makes it stick, but after 500ms (the current value) it closes, but they should at least match each other.