Async interactions - fix "hanging" UI during long running actions

[kulmann]

Async tasks currently have the tendency of blocking the UI. The also get hibernated by the browser when the tab becomes a background tab.

Needs e.g. web workers / separate threads for:

• copy
• move
• delete (especially in batch)
• upload

[kulmann]

Related: we want progress indicators for those interactions, see #6183

[kulmann]

For whoever works on this: have a look at https://github.com/GoogleChrome/workbox first

workbox is unmaintained for 10 months now... doesn't look like a good choice anymore.

Look into https://vueuse.org/core/useWebWorker/ instead.

[ScharfViktor]

When a user deletes a large number of files, the web looks like it is hanging.

• dialog "delete files" hangs
• web is disabled while deleting process
• If we click "cancel" button -> deleting process will contunue until all files are deleted

[lookacat]

Related: #7902

[kulmann]

Related / a very good reason for Web Workers: #10474

[tbsbdr]

Needs research first

[JammingBen]

Closing in favour of these stories:

• [web] Ensure that copy & move operations are not UI-blocking and still running in suspended tabs #10951
• [web] Ensure that trashbin delete operations are not UI-blocking and still running in suspended tabs #10952
• [web] Ensure that restore operations are not UI-blocking and still running in suspended tabs #10953

A web worker for deleting files has been implemented already via #10916.