In the course of making TSFE request/response aware,
we split the rendering preparations of TSFE
into a PSR-15 middleware.

This the first step to extract other parts, like
redirecting to shortcuts/ mountpoints and sending
http headers as well into middleware implementations.

Resolves: #84909
Releases: master
Change-Id: I704ae89a23c8e254574e19a78ecec363f182c747
Reviewed-on: https://review.typo3.org/56833


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>