ref_int - add showcases

### What

Improve current `/showcases` implementation by extending with more examples for modules that are integrated (based on `known_good.json`) and are missing their showcases.

Extend standalone showcases with the examples directly from Modules - same as it is currently done for score_communication.

Create additional complex showcases that will combine multiple Modules.

### Acceptance Criteria (DoD)

Additional examples have been added.
Showcases are building and running for all available configurations.

### How

_No response_