Revert "[FEATURE] Allow PageContentErrorHandler to resolve pages with sub requests"

This reverts commit a848ba4f.

While the feature works well on fully configured sites, in case of errors this is
currently too unstable and may result in infinite recursions when a page is not
configured (for example if no TS Template is present).

When reimplementing we should add more tests and recursion prevention in order to
stabilize the behaviour.

Change-Id: I9f6f5155a78e7d515107f8b6b8d16dc55b78b7dd
Resolves: #90523
Releases: master
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63308


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>