[TASK] Allow string as $subpartContent

The parameter $subpartContent of substituteSubpart() can be either
string or array. IDEs need to have both present in the comment to not
show warnings for given parameters that are correct.

Resolves: #82308
Releases: master, 8.7
Change-Id: Ifcceb8dcd5ad8be56695cef161949046ff74c994
Reviewed-on: https://review.typo3.org/53916


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Jigal van Hemert <jigal.van.hemert@typo3.org>
Tested-by: Jigal van Hemert <jigal.van.hemert@typo3.org>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>

typo3/sysext/core/Classes/Service/MarkerBasedTemplateService.php

@@ -69,7 +69,7 @@ class MarkerBasedTemplateService
      *
      * @param string $content Content with subpart wrapped in fx. "###CONTENT_PART###" inside.
      * @param string $marker Marker string, eg. "###CONTENT_PART###
-     * @param array $subpartContent If $subpartContent happens to be an array, it's [0] and [1] elements are wrapped around the content of the subpart (fetched by getSubpart())
+     * @param string|array $subpartContent If $subpartContent happens to be an array, it's [0] and [1] elements are wrapped around the content of the subpart (fetched by getSubpart())
      * @param bool $recursive If $recursive is set, the function calls itself with the content set to the remaining part of the content after the second marker. This means that proceding subparts are ALSO substituted!
      * @param bool $keepMarker If set, the marker around the subpart is not removed, but kept in the output
      *