Create images for illustrating the structure and workflow

## Description

The Python SDK has documentation, and that is a good starting point for accommodating,
but having some images that show details would help in better understanding the sdk.
For instance, there can be an image illustrating the inner structure of the sdk, a graph with
the classes and the relations between them, or the workflows of different operations:
applying a manifest, creating a workload etc.

Example from Ankaios:
https://github.com/eclipse-ankaios/ankaios/tree/main/api/doc/swdesign/drawio

## Goals

Images are created that illustrate how the SDK works.

## Final result

### Summary

**To be filled when the final solution is sketched.**

### Tasks

- [ ] Analize what can be illustrated.
- [ ] Find a way to programmatically create the diagrams (see example from main repo).
- [ ] Generate the images.
- [ ] Optional: Add the images to the documentation and readme.

まず Python SDK のドキュメントと、issue にリンクされている Ankaios drawio の例を確認します。コミッターとユースケースおよび図について話し合って合意し、その後、それらを生成する方法を選択します。SDK の構造とワークフローが図示され、ドキュメントと README への統合が任意で行われれば完了です。

索引モデルが issue の本文から書いたものです。