[TASK] Remove unused files: images & templates

Most images in typo3/gfx are not used anymore.
Also several html templates are not in use any more.
Removes few image and template files.

Change-Id: Icb609e20a188e19df49aee9173f599af0f087d9a
Fixes: #45785
Releases: 6.1
Reviewed-on: https://review.typo3.org/18455
Reviewed-by: Soren Malling
Tested-by: Soren Malling
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn