[TASK] Use ImageInfo class instead of direct PHP GD call

This ensures maximum compatibility with all available graphics
commands.

Resolves: #78600
Releases: master, 8.7
Change-Id: Id7a95fbdf7782fef59e18de3dc4522d7c68b690a
Reviewed-on: https://review.typo3.org/56622


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Florian Weiss <typo3org@leblanc.at>
Tested-by: Florian Weiss <typo3org@leblanc.at>
Reviewed-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Tested-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Reviewed-by: Frans Saris <franssaris@gmail.com>
Tested-by: Frans Saris <franssaris@gmail.com>