[BUGFIX] Assume image dimension of SVGs with no dimension

Extracting SVG processing to its own processor did not
respect that previously SVG files without dimensions were
handled as a side effect of undefined behaviour without
causing hard errors. The new processor however throws
an exception instead of accepting undefined behaviour, which
causes old installations with such SVG files to break.

As a mitigation (as long as no other correct behaviour is defined),
some default image dimensions are assumed for SVG files where
none can be properly determined.

This does not make SVG files without defined dimensions properly work,
but at least restores the previous behaviour of not throwing
an exception.

Additionally extracting SVG processing uncovered another bug
that existed, but never fully surfaced before.

Processed files that were updated, but in fact were using the
original file (like SVGs typically do) accessed the wrong storage
to fetch file infos, when the processed files were configured to
remain of a different storage. This is now properly checked as well.

Resolves: #92444
Resolves: #92449
Related: #92014
Releases: master, 10.4
Change-Id: Ide10af8105c5fb6a5257aa7a16e48a02a925a8fe
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/65963


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Timo Poppinga <timo.poppinga@zdrei.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Timo Poppinga <timo.poppinga@zdrei.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>