[Task] Create an up-to-date version of the Tutorial

[ichbinrich]

Introduction

During the Summer of 2025 NebulaStream went public after a big refactoring effort, the tutorial is therefore subject to the corresponding update.

Goal

To have a guided tutorial as entry point for general audience into NebulaStream and for newcomers who would like to contribute to NebulaStream.

Criteria

• We want to run the most basic NebulaStream setup with no sources, no queries, so that we have a solid starting point to work on
• We want to read the README.md to be minimal, so that we can do incremental contributions according to what we implement in future issues/PRs

Implementation Hints

• Clean-up the current tutorial repo to implement the new tutorial from scratch
• Update the