[Feature]: Migrate to signal-based input and output

[sdo-1A]

Context

In our showcase / training application, we still use the decorators for Input and Output.
We should migrate to the new signal-based notation.

Proposal

We should migrate to the new notation based on signals:
https://angular.dev/api/core/input
https://angular.dev/api/core/output

Potentially use the existing migration scripts:
https://angular.dev/reference/migrations/signal-inputs
https://angular.dev/reference/migrations/outputs