Fix paste on row while in details view mode
Before this change, right-clicking the row of an unselected item in details view mode would be in a weird state:
- It didn't really count as a click on the item because the item didn't get selected by this click before opening the context menu.
- It didn't really count as a click on the view background either because the actions that showed up depended on the item in that row.
This commit fixes this by considering a right-click in the same row as an unselected item as a click on the view background. The behaviour of right-clicking the icon or name of a file directly is unchanged.
This fixes the following bugs:
- The Paste action that shows up when right-clicking in the unselected row of a folder now works (instead of doing nothing). It now pastes the clipboard contents onto the view background.
- When right-clicking the unselected row of a file (not a folder) a Paste action once again shows up that also pastes the clipboard contents onto the view.
It might make sense to cherry-pick this change to stable.