[CLEANUP] ImportExportController code style

Introduce getters for global objects

Resolves: #57855
Releases: 6.2
Change-Id: I08d37c8934a4b89ef92d31d96073c293a89f04e1
Reviewed-on: https://review.typo3.org/29411
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Oliver Klee
Reviewed-by: Stefan Neufeind
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring