[BUGFIX] Fix bug in Popover.setOptions and add JSUnit tests

Resolves: #78396
Releases: master
Change-Id: I9a132a547b3be04417094b3ce5a2e1eed6dd843c
Reviewed-on: https://review.typo3.org/50339


Reviewed-by: Stefan Bürk <stefan.buerk@impactmedia.de>
Tested-by: Stefan Bürk <stefan.buerk@impactmedia.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>