Add feedback while opening Wi-Fi settings from Tor Connection

Right now there is no feedback. We should have a spinner.

See:

• a previous attempt that broke things: #18594 (comment 277474)
• for some context about the current code: 2975b6f0 and #18587 (closed)

To Do

• Verify that we get feedback
• Verify that the Wi-Fi settings appear when started from Tor Connection
• Verify that one can connect to a Wi-Fi network from the GNOME settings started from Tor Connection