Make the inspector item context commands work on the selected item when not invoked via the buttons

[Peter Strömberg]

Currently the only way to invoke the commands for inspector items is to click the hover buttons. So the user can't e.g. bind keyboard shortcuts to inspect an item or clear, or copy it's text.

We can make the commands behave such that if they are not invoked from the context buttons they will be invoked on the selected item, if any, otherwise the latest added (topmost) item.