[TASK] Properly reset unit test singletons

typo3/testing-framework since version 3.8.0 can reset
singletons created by makeInstance automatically
if $this->$resetSingletonInstances is set to true.

This version additionally checks for left over singletons
in case that property has not been set and lets tests
fail in this case.

composer require --dev typo3/testing-framework:^3.8

As advantage, a manual backup of singleton instances
within tests is not needed anymore.

The patch comes with a set of test case adaptions to
cope with this new situation.

Change-Id: Ib5f278145e385e32d543541872cf5e1f208fad47
Resolves: #85209
Releases: master
Reviewed-on: https://review.typo3.org/57169


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Joerg Boesche <typo3@joergboesche.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>