[TASK] Deprecate StandaloneView for EXT:form EmailFinisher

With #90728 FluidEmail was added to the EXT:form EmailFinisher.
Therefore the StandaloneView has now been deprecated along with
the corresponding configuration option `templatePathAndFilename`,
which can't be used for FluidEmail.

Resolves: #92435
Releases: master
Change-Id: Iabda1d36b03f347d752f19452c2e3392990d303d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/65921


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Marcus Schwemer <ms@schwemer.de>
Reviewed-by: Benni Mack <benni@typo3.org>