Extend image toolbar button to browse for file

Why the new feature should be added

The Paste Image toolbar button currently expects image data on the clipboard, such as image data from a graphics app, or an image file copied from a file manager.

If the clipboard does not contain an image, it throws an error:

How the new feature should work

While this error clearly explains that an image should be copied beforehand, instead of asking the user to start over, it might be better to allow them to continue by providing an option to browse for an image file if the clipboard does not contain image data.