Add feedback when opening desktop launchers

Originally created by @sajolida on #15101 (Redmine)

Currently there’s no feedback when opening the desktop launchers. Starting apps via the Applications menu is out of scope here, see #15738 (closed).

These can take quite some time to take action, for example several seconds to open the documentation, and lead people to believe that they haven’t clicked correctly.

This was reported by huertanix when training journalists who are new to GNOME.

During the user testing of the Additional Software beta, I also saw 4 out of 5 participants open an application multiple times by mistake. All 5 participants were otherwise GNOME users so this issue is affecting quite frequently experienced users as well.

According to Florian Müllner there’s a freedesktop specification to provide feedback when launching applications.

Feature Branch: feature/15023-tor-browser-8

Parent Task: #14548

Related issues

• Related to #15528
• Related to #14544 (closed)
• Related to #15738 (closed)
• Related to #15546 (closed)
• Related to #15855 (closed)
• Blocked by #15023 (closed)