Update DatabaseQueryProcessor.php

This makes it possible, to configure only one field of the result.
We have a link field, which wasn't parsed as typolink. But we didn't want to define every single field of the query. So we added the key "overrideFields".
e.g.:

20 = FriendsOfTYPO3Headless\HeadlessBootstrapPackage\DataProcessing\DatabaseQueryProcessor
20 {
  table = tx_bootstrappackage_carousel_item
  pidInList.field = pid
  where {
    data = field:uid
    intval = 1
    wrap = tt_content=|
  }
  overrideFields {
    link = TEXT
    link {
      field = link
      htmlSpecialChars = 1
      typolink {
        parameter {
          field = link
        }
        returnLast = result
      }
    }
  }
  orderBy = sorting
  as = records
}

Classes/DataProcessing/DatabaseQueryProcessor.php

@@ -129,6 +129,16 @@ private function processRecordVariables(array $records, string $tableName, array
 
             $processedRecordVariables[$key] = $record;
             $processedRecordVariables[$key] = $this->contentDataProcessor->process($recordContentObjectRenderer, $processorConfiguration, $processedRecordVariables[$key]);
+
+            if (isset($processorConfiguration['overrideFields.'])) {
+                $overrideFields = $this->typoScriptService->convertTypoScriptArrayToPlainArray($processorConfiguration['overrideFields.']);
+                $jsonCE = $this->typoScriptService->convertPlainArrayToTypoScriptArray(['fields' => $overrideFields, '_typoScriptNodeValue' => 'JSON']);
+                $record = \json_decode($recordContentObjectRenderer->cObjGetSingle('JSON', $jsonCE), true);
+
+                foreach ($record as $fieldName => $overrideData) {
+                    $processedRecordVariables[$key][$fieldName] = $overrideData;
+                }
+            }
         }
 
         return $processedRecordVariables;