[TASK] Refactor unit test to cover stdWrap_replacement

- Refactor the unit test of stdWrap_replacement to test the method
  replacement instead.
- Add another test to show that stdWrap_replacement delegates to
  the method replacement.

Releases: master
Resolves: #76770
Change-Id: I44e5c16cc9c5d9c44e0b79b8eca01e8b96bc956b
Reviewed-on: https://review.typo3.org/48684


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