[TASK] Finetune avatar size in backend toolbar

Resolves: #80501
Releases: master
Change-Id: I5371b546bb7ebffdfc78a5bbfe1b86699a4f4a43
Reviewed-on: https://review.typo3.org/52198


Reviewed-by: Jigal van Hemert <jigal.van.hemert@typo3.org>
Tested-by: Jigal van Hemert <jigal.van.hemert@typo3.org>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>