[BUGFIX] Pad multibyte strings correctly

A new function StringUtility::multibyteStringPad() is
introduced to handle multibyte strings instead of
str_pad() which will not pad strings with multibyte
characters correctly.

The new function is now used for:

- Fluid ViewHelper format.padding
- TypoScript stdWrap.strPad

Resolves: #95189
Resolves: #95190
Releases: master
Change-Id: I4b8bf4b42e049b17754b260003ac064fbbb6246a
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/71032


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>