GUI: Show a list of pinned stuff fetched from all registered Pups

[akavel]

GUI:

• Show a list of pinned stuff fetched from all registered Pups
• (OPTIONAL) ideally, with tiny previews (only for images)

—> table with columns:

• img_preview(optional!);
• filename(if possible?);
• hash;
• [ ] pinata;
• [ ] other_svc;
• [ ] rasp_pi;
• [ ] ...