[TASK] Stabilize acceptance tests

Some acceptance tests fail radomly due
to speed/timing of the checked elements
or unresolved promises.

This should be avoided now by using "waitForElements"
instead of "canSeeElement". This may cause longer
test runs but makes sure tests won't fail
on performane hiccups.

On top of that Icon.getIcon in DocumentSaveActions
will catch unresolved promise in case a new page or reload
was triggered by the button to avoid Javascript errors.
For example in Scheduler -> Add Task and hit save.

Resolves: #95070
Releases: master
Change-Id: I927876ecfd46cbc2edae03db249982fcb8a9d2f0
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70860


Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Benni Mack <benni@typo3.org>