Fix Output creation on the Stream details page

[ousmaneo]

Fixes stream Data Routing output type handling so configuration definitions are resolved from the correct flat map shape and shared lookup helpers are used consistently across stream and output flows.

fix #23793

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (non-breaking change)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have requested a documentation update.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.