[TASK] Refactor unit test to cover stdWrap_strPad

Resolves: #76756
Releases: master
Change-Id: I78d1b112cd6f292cc19b28779c760bf5289d8c07
Reviewed-on: https://review.typo3.org/48653


Reviewed-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Daniel Goerz <ervaude@gmail.com>
Reviewed-by: Joerg Boesche <typo3@joergboesche.de>
Tested-by: Joerg Boesche <typo3@joergboesche.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>