Set dynamically uuid and guid

[damien-carcel]

All the images contain a docker user (uuid and guid 1000). As most Linux systems have their first default user with this ID, this works well in most cases.

However, some systems, like Ubuntu, create their first user with 1001 as uuid and guid, and then nothing works as expected.

Solution is to:
- [ ] change uuid and guid, only if needed, in the entrypoint,
- [ ] pass the host uuid and guid as environment variables (in the compose files).
How to do that: https://muffinresearch.co.uk/linux-changing-uids-and-gids-for-user/
This solution is impossible to use, as the docker user is already used when we attempt to change its IDs.

Another solution would be to remove completly the user (will be a big BC break regarding the compose files used in the different versions of the PIM), and directly pass the IDs to a "FPM start script".

[damien-carcel]

Closed in favor of #322.