[TASK] Refactor unit test to cover stdWrap_strftime

Releases: master
Resolves: #76779
Change-Id: I174b1922dfd39d04a6f5ace6c3be7bc317a46447
Reviewed-on: https://review.typo3.org/48685


Tested-by: Bamboo TYPO3com <info@typo3.com>
Reviewed-by: Daniel Goerz <ervaude@gmail.com>
Tested-by: Daniel Goerz <ervaude@gmail.com>
Reviewed-by: Susanne Moog <typo3@susannemoog.de>
Tested-by: Susanne Moog <typo3@susannemoog.de>