[TASK] Add warning in Reports module if content adapter is active

The setting [FE][activateContentAdapter] has a large impact on
performance. A warning in the Reports module will encourage
integrators to adapt TypoScript to increase performance.

Resolves: #57249
Releases: 6.2
Change-Id: I935b86ba701d3b0dbac3b807a1ae9312bff223fc
Reviewed-on: https://review.typo3.org/28724
Reviewed-by: Wouter Wolters
Reviewed-by: Alexander Opitz
Tested-by: Alexander Opitz
Reviewed-by: Markus Klein
Tested-by: Markus Klein