Some cache backends have specific sql resource files located at
t3lib/cache/backend/resources.
After namespace switch, the class files are located at ext:core.
According to the extbase scheme, the resource files are now moved
to ext:core/Resources/Private/Sql/Cache/Backend and renamed.

Change-Id: Ib693e0dfed8636b9898ef9bbff73dab21df5c2b0
Resolves: #46263
Releases: 6.1
Reviewed-on: https://review.typo3.org/18895
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn