[BUGFIX] Wrong file icon in info popup

In the info popup of a file/folder the wrong icon is shown.

This patch changes it so IconUtility::getSpriteIconForResource()
is used and moves the rendering of the header to the
DocumentTemplate.

Resolves: #56251
Releases: 6.2
Change-Id: I7fc40af85b8bc623112bcec29c2409221a937718
Reviewed-on: https://review.typo3.org/27819
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn