When opening a EuiContextMenu, there are some inconsistencies regarding the hover/active state.

Tested on macOS Big Sur, Firefox 91.

When hovering over the menu elements

• The first element keeps the blue background, no matter where the user hovers.
• In some cases the hovered element doesn't get an underline (see "Go to a link" in the attached video.)
• When going to a nested panel, the default active element (the one with the blue background) is the second, no the first.
• When going back, no element is marked as active element

When navigating menu elements with the arrow keys.

• When the menu first opens, it takes two presses of the down arrow key to move down.
• When the first menu element is selected, it takes two presses of the up arrow key to cycle to the last menu element.
• When the last menu element is selected, it takes two presses of the down arrow key to cycle to the first menu element.