[TASK] Slightly improve database reference index error rendering

Reference index errors are now rendered as a list.

Resolves: #100509
Releases: main
Change-Id: I8e46ea6e480172891a64424acb8c8e4acb3204dc
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78516


Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>

typo3/sysext/lowlevel/Resources/Private/Templates/ReferenceIndex.html

@@ -19,9 +19,11 @@
         <f:be.infobox state="{f:if(condition:'{referenceIndexResult.errors}', then:'1', else:'0')}" title="{referenceIndexResult.resultText}">
             <f:if condition="{referenceIndexResult.errors}">
                 <f:then>
-                    <f:for each="{referenceIndexResult.errors}" as="error">
-                        {error}<br/>
-                    </f:for>
+                    <ul class="list-unstyled">
+                        <f:for each="{referenceIndexResult.errors}" as="error">
+                            <li>{error}</li>
+                        </f:for>
+                    </ul>
                 </f:then>
                 <f:else>
                     <f:translate key="LLL:EXT:lowlevel/Resources/Private/Language/locallang.xlf:refindex_ok"/>