TYPO3 Core

Implementing a preliminary parsing code and having an
assumption on the existence of a .env file and a hardcoded
location of that file, makes TYPO3 again implement a speciality
instead of using standard tools.

Therefore the .env reading and parsing is removed in favor
of reading the values directly from the environment, which
gives users the option to choose their own .env solution, or rely
on just setting the env vars.