[BUGFIX] Wait some seconds before click in modal content

Some acceptance tests fails because of a timing issues. If a modal is not
ready the next click fails. This patch adds a wait before click.

Resolves: #84806
Releases: master
Change-Id: Idb41eee4930441c36f99a8f5d5faa0e74c380a5c
Reviewed-on: https://review.typo3.org/56749


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Mona Muzaffar <mona.muzaffar@gmx.de>
Tested-by: Mona Muzaffar <mona.muzaffar@gmx.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>