ProjectExplorer: Remove ProjectConfiguration base from Target

Targets are different from {Run,Build,Deployment}Configurations,
both regarding the level in the ProjectExplorer hierarchy, and
also by the set of supported operations (e.g. aspects).

Change-Id: Ia8490e2280a9ecc518395c5e48ce2fd5d6d58fd2
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/ios/iosbuildstep.cpp

@@ -129,6 +129,10 @@ public:
             if (pc && pc->isActive())
                 updateDetails();
         });
+        connect(pro, &Project::activeTargetChanged, this, [this](Target *target) {
+            if (target && target->isActive())
+                updateDetails();
+        });
     }
 
 private: