Pin the detail panel
The Detail Panel should be pinnable by the user. If pinned it stays open even if there is no selection. In this case the detail should show nothing and still occupy screen space.
Note that this feature request possibly violates the DMX Webclient deep link principle. I assume the detail panel pinned state is neither reflected in the browser URL nor persistent in any way. As a consequence when an empty detail panel is shown, reloading the page will clear the pinned state, that is the detail panel is now closed (because there is no selection).
The general DMX Webclient principle is that (for a logged in user) after page reload the page content/layout is exactly the same. That is user A can share an URL and be sure user B sees exactly the same screen when opening that URL. This principle is now violated.
This is a follow-up of dmx-intern/feature-planning#42