[BUGFIX] Make line height configurable for Gifbuilder

If `lineHeight` is set then its value would be taken
as line height instead of line height calculated from given text.

Resolves: #22399
Releases: master, 8.7
Change-Id: Ibc38559a6c7fc616c2b25b419a3bc6feddf87a61
Reviewed-on: https://review.typo3.org/56327


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>