[BUGFIX] Fix TypeError in InlineControlContainer

In case a TCA column with type=inline does not
contain "container controls", e.g. the `languages`
column in a site configuration, a TypeError was
triggered by the toggleContainerControls() method.

This is fixed by proper type checking.

Resolves: #93690
Releases: master, 10.4
Change-Id: I6dc0a874adddb6e9c56565087b090072656b54eb
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/68301


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>