new example: parallel operations

[jonathanlukas]

Description

This example shows how to run Camunda 7 embedded next to Camunda 8 and use the same functions for delegates and job workers at the same time.

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:

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