Add button to open files in file manager in recent activity window and sync conflicts

In the systray window for each recently synced file there is a ... button which gives options for 'Link Share' and 'Internal link' but no direct way to open the file location in the system file manager. This means to find the file you have to copy the internal link and paste it into a file manager dialog and edit it because it's a URL and file manager doesn't like the file:// prefix. It should be easier to find the file on your system.

This would be especially useful in the Sync Conflicts dialog.

Also useful would be a 'Copy file path' option to get the path without the url prefix.

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## Feature request

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