Improve action popover implementation - hiding/showing + styles

Part of #2352 (closed)

• manually open/close popover

  • when the cursor leaves the action button or the popover, we start counting down 200ms before hiding the popover
  • when the cursor enters the action button or the popover, we stop the countdown

• use global (unscoped) styles for the popover so it doesn't need to be inside of the button