Allow to delete "file" attachments

[stefan-niedermann]

A quick test showed, that deleting the new "file" attachments via the Android app doesn't do anything on the server side. I therefore temporarily hid the delete button.

• [ ] Reenable the delete button
• [ ] Make sync great again

[desperateCoder]

(Documentation for later implementation, need to leave now)

Looks like the ID of the file is kind of different. I tracked the Web-UI call and saw this:

DELETE | https://myFancyURL.tld/index.php/apps/deck/cards/611/attachment/file:55

I guess the prefix for the ID has to be file:, tho I can't tell why the path is different to the official documentation.

Worth a try!

[stefan-niedermann]

Did some work on the 871-delete-attachments-for-1-3 branch. Though i think reverse engineering the Web UI isn't really a good idea. The URL starts with /apps/deck for example, instead of /api/deck. I differentiate on the branch so we can easily add the file: if necessary, but simply adding file: to the old API doesn't work (HTTP 405) unfortunately.

[stefan-niedermann]

Issue in the server app: https://github.com/nextcloud/deck/issues/2904

[stefan-niedermann]

Fixed shipped in Deck Android 1.24.0.