Add a testbed project for watchOS

### What is the problem or limitation you are having?

There's not currently any way to (easily) test the operation of watchOS.

### Describe the solution you'd like

The Python patch should be extended to include a testbed project for watchOS.

### Describe alternatives you've considered

None

### Additional context

watchOS projects are quite different to other platforms; however, it may be possible to crib a lot of content from the iOS testbed project.

It may also be worth investigating if a single testbed can be used for all Apple platforms, with multiple targets in a single project.

Commencez par localiser le patch Python et le projet de testbed iOS existant, puis comparez la structure de son projet et de ses targets. Déterminez si watchOS nécessite un testbed séparé ou s’il peut partager un projet Apple multi-targets ; le travail est considéré comme terminé lorsque le dépôt inclut un testbed watchOS opérationnel et que l’approche du projet est établie.

Rédigé par le modèle d'indexation à partir du texte de l'issue.