[BUGFIX] Get suggest wizard working with renderMode=checkbox

In case a select field with renderMode "checkbox" is used together with
the suggest wizard, clicking the suggestions will not check the
related item in the list and therefore the wizard isn't useful anyhow
in that combination.

Fixes: #21924
Releases: 6.2, 6.1, 6.0
Change-Id: I5823197e9f6bb3f3d4ffc4032677478bd18d87f3
Reviewed-on: https://review.typo3.org/18689
Reviewed-by: Markus Klein
Tested-by: Markus Klein
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters