[BUGFIX] Sprite icons not shown

If first hit after clearing cache was not in BE context
some icons are not part of the sprite css.

This patch makes sure that these icons are registered
in every context.

Releases: 6.2
Resolves: #58758
Change-Id: I4c44c0f241f096c15e8257975b665ec89b60d2e4
Reviewed-on: https://review.typo3.org/30046
Reviewed-by: Fabien Udriot
Reviewed-by: Helmut Hummel
Tested-by: Helmut Hummel