[TASK] EXT: tstemplate - use treeline sprite icons

Bring treeline sprite icons to t3-table in Template backend module.

Resolves: #56229
Releases: 6.2
Change-Id: I95cfad211fe5750d0786592986b4849f5f5b9826
Reviewed-on: https://review.typo3.org/27800
Reviewed-by: Markus Klein
Tested-by: Markus Klein
Reviewed-by: Marcin Sągol
Tested-by: Marcin Sągol
Reviewed-by: Benjamin Mack
Tested-by: Benjamin Mack