"Open in terminal" has disappeared from the file explorer

Originally created by @tobtoht on #17186 (Redmine)

In Tails 4.0 the menu option to open the terminal in the current directory by right clicking on empty space within the file explorer has disappeared.

This significantly hinders those that want to run scripts or develop on Tails.

Feature Branch: bugfix/17186-open-in-terminal

Edited May 21, 2020 by tobtoht

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