Simplify/fix basic docker setup for single instances

[philippotto]

If I simply run wk with docker on a server with ip X, I'd like to be able to visit http://X:9000 and everything should just work. Instead, the communication with the datastore fails since it wants to communicate with localhost.

At the moment, I change the datastores manually within the database that gets reset by wk sometimes.

It would be cool if we could make this scenario more hassle-free.

[normanrz]

To implement this, I believe, we need an additional publicUrl for data and tracing stores. webknossos and the stores would continue to use the url and the frontend would use the publicUrl. The rest can be done with some docker-compose magic.
The data and tracing stores probably don't need to know the publicUrl of webKnossos since they are not creating user-facing links?

pinging @fm3 @youri-k

[fm3]

sounds about right to me

[youri-k]

@normanrz @fm3 the backend part should be finished and ready for review

[fm3]

@youri-k that’s #4286, right? could you fill in the template so that we know what to look for?

[normanrz]

I think your PR can be merged w/o the work that I still need to do.