[BUGFIX] Avoid RTE context menu collapse to arrows only

Solves an issue in Chrome where calculating the height of
the editor window returns zero. Solved by hardcoding a
minimum context menu height of 150 pixels; applied via
Math.max()'ing the resolved height and 150.

Change-Id: Ie79507d661128f6aff31c12573b9c020b913ec8a
Resolves: #78795
Releases: master, 7.6
Reviewed-on: https://review.typo3.org/50779


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Gianluigi Martino <gmartino27@gmail.com>
Tested-by: Gianluigi Martino <gmartino27@gmail.com>
Reviewed-by: Markus Sommer <markussom@posteo.de>
Tested-by: Markus Sommer <markussom@posteo.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>