Popovers - fix FocusTrap and close functionality

[KStClaire]

Currently, when a Popover contains a form element, the Popover will appear but never properly close. With the recent addition of the close button (#57) to non-form popovers, we need to extend the functioning close button to form popovers as well.

Some complications stemming from FocusTrap:

• Currently only surrounds the popover's body content, which leaves the close button out of reachable focus. It's the same when trying to click outside of the popover.
• FocusTrap cannot currently wrap Popover either, as this causes numerous breaks in both styling and popover function.

We need to update FocusTrap and/or PopoverTrigger to allow for the close button to be focusable/clickable.