[TASK] Use root paths for fluid templates in indexed_search

The extbase/fluid plugin of indexed search still uses the deprecated
rootPath for templates, partials and layouts. This patch adjusts the
typoscript to use rootPaths.

Change-Id: I7fc164d3ef14aaa1674f3f7940e2cd921a0a9216
Resolves: #72051
Releases: master
Reviewed-on: https://review.typo3.org/45118


Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Markus Sommer <markussom@posteo.de>
Tested-by: Markus Sommer <markussom@posteo.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Tested-by: Tymoteusz Motylewski <t.motylewski@gmail.com>