[TASK] Add EXT:dashboard to test environment

Enables EXT:dashboard when running tests which
required a few changes to wait for pageTree to be
fully loaded

Resolves: #94373
Releases: master
Change-Id: If9f91626f03e9b95e0c26c4a3a264aa0f064d412
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/69519


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>