remove StorageSelector since cardinality has been changed to 1..1 again. So there will be only 1 valid StorageService at a time

Signed-off-by: Thomas Eichstädt-Engelen <thomas.eichstaedt-engelen@innoq.com>
moved some code

Signed-off-by: Thomas Eichstädt-Engelen <thomas.eichstaedt-engelen@innoq.com>