When extbase has been changed to PSR-7 responses,
class ReferringRequest has been nearly obsoleted:
It is only used to be immediately turned into a
ForwardResponse.
To further prepare towards PSR-7 requests, usage of
ReferringRequest which extends extbase Request is
dropped and the class marked as deprecated.

Change-Id: If16c09b0601792f6702fbacee064cd4d514c70c6
Resolves: #94367
Related: #92502
Releases: master
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/69513

Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>