Subspace templates: show in global library

[SimoneZaza]

Description

As a user, I want to see all the templates that are available

Acceptance criteria

• [ ] Add subspace templates to the "all available materials" block
• [ ] Use cards from #6787
• [ ] Clicking on card opens preview from #6799

Additional Context

Screen shots / UX designs / data that are relevant.

Areas that will be affected

To be added during the refinement