[Task] naming of shared aspect models in workspace

[BirgitBoss]

Is your task related to a problem? Please describe.
As a modeller I need first to store shared aspect models in the workspace, otherwise I cannot edit the aspect model with the aspect itself.
Shared models in my understanding are those models that do not contain aspect definitions but only shared elements like Entities or Characteristics.

Two use cases:

• build a new share model within editor
• load shared model from file system
  and then File/Save to Workspace

Current behavior:

• The name of the new file is NewModel.ttl
• The file name cannot be changed in the editor. this means it is not possible to create more than one shared file within a namespace.

Describe the solution you'd like

• enable renaming of files within workspace
• ask for name before storing file in workspace if it is a new model created in editor, propose something
• if shared model was loaded from file system use the same file name when storing to workspace
• use different default name, e.g. newModel_shared.ttl

[chris-volk]

Whenever an Aspect Model file has an aspect, the default file name should be the Aspect name.
For an aspect model file without an aspect, the default file name should be empty to promote users finding a file name that captures the intention of the file and avoid the bad practice of calling things "shared".