[BUGFIX] Fix PHP warnings in functional tests

Some PHP warnings occur in functional tests due
to missing initialization of arrays or unused
function parameters.

Resolves: #56203
Related: #56187
Releases: 6.0
Change-Id: I1cd75de253382759315a8f72cff6e497b31bcc07
Reviewed-on: https://review.typo3.org/27785
Reviewed-by: Helmut Hummel
Tested-by: Helmut Hummel