[BUGFIX] Fixes search with search type "sentence"

With this commit the method getSearchWords is called
after initializing $this->searchData, which is used there (only when
searchType is 20 - search for "sentence")

Resolves: #75845
Releases: master, 10.4
Change-Id: Ic344f05fb6f4ac1ef496907edfc4fa0e49010401
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/68369


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>