Poor error handling when navigator.clipboard-based paste or paste special fails

[vmiklos]

Describe the Bug

When we try to use the new navigator.clipboard-based paste / paste special in Chrome and the permission is not granted, then the error handling behavior is worse in Firefox where we don't try to use navigator.clipboard.

Steps to Reproduce

1. Create a Calc document, put 1 and 2 to cells, a SUM() formula to a 3rd cell.
2. Copy the formula using Ctrl-C.
3. Click paste special in the notebookbar and reject the permission popup.

Expected Behavior

A popup is shown that you need to use Ctrl-V and the popup disappears when Ctrl-V is pressed, as in Firefox.

Actual Behavior

Nothing happens, just an error message in the devtools console.

Screenshots

Console output:

navigator.clipboard.read() failed: The Clipboard API has been blocked because of a permissions policy applied to the current document. See https://goo.gl/EuHzyv for more details.

Additional Context

This problem is specific to Chrome, it won't happen in Firefox.

[vmiklos]

nextcloud/richdocuments#3474 for the nextcloud/richdocuments side of this.

[vmiklos]

#8306 fixed the COOL side.