ICU tokenizer doesn't need any extra data anymore, so it doesn't
make sense to create a directory which then remains empty. If a
tokenizer needs such a directory in the future, it needs to create
it on its own and make sure to handle the situation correctly where
no project directory is used at all.
Automatically repopulate the tokenizer/ directory with the PHP stub
and the postgresql module, when the directory is missing. This allows
to switch working directories and in particular run the service
from a different maschine then where it was installed.
Users still need to make sure that .env files are set up correctly
or they will shoot themselves in the foot.
See #2515.
