Bugfix: Inline child translations are in the reference index 

Description 

The DataHandler command deepltranslate for an inline child localizes it through its translated parent, with a DataHandler of its own. That is the case for "Translate with DeepL" of an inline child, the localization wizard, web-vision/deepltranslate-mass and the inline translation of web-vision/deepltranslate-auto-renew. TYPO3 updates the reference index at the end of the outermost DataHandler only, and this DataHandler is never the outermost.

The child translation and the relation of the translated parent to it were missing from the reference index. The file reference of a translated content element, for example, was not counted as a use of the file, and a check of the reference index reported both records.

Impact 

The reference index is updated for the records written when an inline child is translated with DeepL. The DataHandler localizing the child works with the backend user of the DataHandler that runs the command.

Inline children translated before this version keep the reference index they had. Update the reference index once to correct it:

vendor/bin/typo3 referenceindex:update

See pull request #698.