Feature Request: Find orphaned keys in TYPO3 installations

[peterkraume]

It would be extremely helpful to be able to find orphaned keys in TYPO3 extensions.
I know the key is often compiled programmatically, but a check like this would provide useful information about where to look.

[konradmichalik]

Hej @peterkraume,
I had already thought about this idea once before, but I had provisionally rejected it.

It will not be easy to find all the places where the keys are actually used. In addition to Fluid and TCA, there may be many other places, often programmatic, where a key is used. I was concerned that this could lead to too many false-negative results.

Nevertheless, Symfony has a similar command that can find orphaned keys (at least in the template): https://symfony.com/doc/current/translation.html#how-to-find-missing-or-unused-translation-messages