Clicking on large folders/listing a large amount of pins stalls the UI

[RubenKelevra]

Describe the bug
The UI cannot handle long lists of items

To Reproduce
For me listing my 6k pins doesn't work. The UI just stalls and works endlessly on this task, until chrome asks to close the page.

Expected behavior
Just the first two dozens or so items are fetched and displayed. Since the total number is already known, they could be shown as pages.

Also, operations that take longer than something like 1 second should get a progress bar and not stall the browser tab. There should also be an abort button.

Screenshots

Desktop (please complete the following information):

• OS: Linux
• Browser Chrome
• Version 79