[BUGFIX] Use original file for ProcessedFile::getMimeType and ::getSize

When the processed files are saved in a different storage,
calling `$this->getStorage()->getFileInfoByIdentifier()`
on a ProcessedFile that uses the original file will fail.

This patch proxies the calls to the original file if necessary,
just as it is already done for e.g. exists() and getPublicUrl().

Resolves: #102267
Releases: main, 12.4
Change-Id: I862340e377eef306c906bf35bf171a82876fdc01
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/81593


Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Guido Schmechel <guido.schmechel@brandung.de>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Garvin Hicking <gh@faktor-e.de>
Tested-by: Garvin Hicking <gh@faktor-e.de>