Improve methods order

## Description

The methods of a class should follow an ordering convention. Currently, all the methods are placed by either their usecase or just randomly in the class. The order should be like this:

1. Class-level attributes
2. init()
3. Magic methods like str, len, ...
4. Public instance methods
5. private or protected methods
6. static and class methods
7. cleanup (del)

Comment that mentioned this: https://github.com/eclipse-ankaios/ank-sdk-python/pull/43#discussion_r1867710186

## Goals

The code is refactored and the methods are in a proper order.

## Final result

### Summary

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

### Tasks

- [ ] Reorder the methods in the sdk
- [ ] Optional: Reorder the unit test methods to match the implementation

Start by inventorying the SDK classes and their current method order, then inspect the unit test methods to determine whether they mirror the implementation. Discuss the intended use case and workflow with the committers before changing anything. Done means SDK methods follow the six-part ordering convention, with unit tests optionally reordered to match.

Written by the indexing model from the issue text.