replace inflector

[DavidBruchmann]

The inflector class is pretty old and the source not even available anymore apart from the web-archive.
So it's not maintained and there is no support.

Without having verified the solutions in detail I propose one of the following solutions:

• https://github.com/symfony/symfony/blob/7.2/src/Symfony/Component/String/Inflector/EnglishInflector.php
  https://github.com/symfony/symfony/blob/7.2/src/Symfony/Component/String/Inflector/FrenchInflector.php

• https://github.com/doctrine/inflector/
  several languages: English, French, NorwegianBokmal, Portuguese, Spanish, Turkish

I didn't verify though if there have been adjustments, so if own maintenance had been done.