new example: async-retry-counter

[jonathanlukas]

Description

This example shows how a retry counter can be implemented for async communication

Additional context

Types of changes

• [ ] Bug fix (non-breaking change which fixes an existing open issue)
• [x] New example (non-breaking change which adds functionality to an extension)
• [ ] Documentation update (changes made to an existing piece of documentation)

Checklist:

• [ ] My code is formatted by spotless
• [x] I have added at least one meaningful test to assert the behaviour of the example.
• [ ] I have created documentation that informs about the purpose, the functionality and how to setup the example
• [ ] I have added a build job for my example to .github/workflows/build.yaml