[TASK] Show information text as infobox in EXT:indexed_search

If no page has been selected in the "Indexing" backend module, an
information is displayed. This text is now displayed in the typical
infobox style instead of as a heading.

Resolves: #103590
Releases: main, 12.4
Change-Id: I6e44c5ad8502eb7ecb71581cb11084543c3e13aa
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83732
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>

typo3/sysext/indexed_search/Resources/Private/Templates/Administration/Statistic.html

@@ -143,7 +143,10 @@ <h1><f:translate key="administration.statistics" /></h1>
             </div>
         </f:then>
         <f:else>
-            <h2><f:translate key="administration.noPageSelected" /></h2>
+            <f:be.infobox
+                message="{f:translate(key:'LLL:EXT:indexed_search/Resources/Private/Language/locallang.xlf:administration.noPageSelected')}"
+                state="-1"
+            />
         </f:else>
     </f:if>
 </f:section>