[BUGFIX] Load ClickMenu JavaScript in "Backend users" module

This patch adds the ClickMenu JavaScript to enable the click menu after
clicking the avatars.

Resolves: #77680
Releases: master, 7.6
Change-Id: I50025e97649957ffdc13abe974c5ce6f6df5f198
Reviewed-on: https://review.typo3.org/49632


Tested-by: Bamboo TYPO3com <info@typo3.com>
Reviewed-by: Philipp Gampe <philipp.gampe@typo3.org>
Tested-by: Philipp Gampe <philipp.gampe@typo3.org>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>