Notebook Activity must support Notebook name resolution within a dynamic workspace

## Requested behavior

The Fabric Pipeline Notebook Activity should support selecting a notebook by a

stable Notebook name while the Workspace ID is dynamic.

Example:

- Workspace ID: `@pipeline().DataFactory`

- Notebook name: `nb_name`

At runtime, Fabric should resolve the Notebook name within the supplied

workspace and execute the matching local notebook.

The pipeline definition must not require a workspace-specific physical Notebook

GUID. The GUID is an internal implementation detail that changes after Git

Sync to another workspace and makes versioned pipeline artifacts non-portable.