Add the remote user configuration in base Dockerfile

[domire8]

Hi guys, so I've been working on that image for the network-interfaces and I realized that we always have to configure a remote user when we use control-libraries/Development-dependencies, and its always the same lines we have to use everywhere.

So I'm suggestion to put that user configuration into the base dockerfile of control-libraries, equivalent to the ros2_ws image. This would allow us internally to use aica-docker commands with images that are based on control-libraries/development-dependencies. Now I'm quite sure this will require some discussions between us, which is why this PR is not finished yet. In particular, I need to have the sshd_entypoint script somewhere so I can copy it in the image, so I'm wondering what to do there. Cloning docker-images and copying the file from there might not be the best approach because we always said we wanna have control libraries independent from docker-images.

What do you think? Is this something you find acceptable and if yes, how should we handle the entrypoint script? I personally think it would be useful because again, we are the only users of control libraries and we can even make the build-test.sh and dev-server.sh scripts here work without aica-docker commands.

[domire8]

In the third commit, I renamed our user from remote to developer (such that it also makes sense for non-remote stuff, such as the demos), I copied and pasted the sshd entrypoint script and the relevant lines from the aica-docker server script for the dev-server.sh script in source.

[domire8]

I've also updated all the demos, even though its not as important. If you're happy with the changes in source, python and the base Dockerfile, I think we are good to go. It's all tested and works like expected

[domire8]

Closing this in favour of #244