Subtask of {T7682}
https://bugs.kde.org/show_bug.cgi?id=384936
Right now, when you use Discover to install a program, you can easily launch it from Discover itself, but thereafter, it may seem to be "lost" to a new user. The two major program-launcher UIs (Kickoff/Kicker and the Task Manager) don't in any way display or highlight the newly-installed app. We should find a way to make this much more obvious so users know where to find apps after installation once they close Discover, or else they may think that they have to launch Discover to open their apps (yes, really...). Also applicable to the Usability & Productivity initiative.