Widgets in Talk don't unlock file after leaving chat

[pschopen]

When a file is loaded in a widget richdocuments acquire the lock, but it does not release it on close (close meaning navigating away).
The lock should be released when the editing session ends

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When a file is shared within a talk chat the widget function loads the file automatically. Then the user "joins" NC Office and the file gets locked. Unfortunately it doesn't get unlocked when the chat is left. The file is then still locked by "Nextcloud Office"

[juliushaertl]

We probably should adapt the fix like we do it in text: nextcloud/text#5863