ProjectExplorer: Add a RunConfigurationFactory::canHandle(Target *)

All RunConfiguration factories had some kind of canHandle(Target *)
implementation. Centralize this notion.

Change-Id: Ie24a355e857bddfd76b866859b8c7a42ffc83840
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/cmakeprojectmanager/cmakerunconfiguration.h

@@ -94,9 +94,6 @@ public:
 
     static Core::Id idFromBuildTarget(const QString &target);
     static QString buildTargetFromId(Core::Id id);
-
-private:
-    bool canHandle(ProjectExplorer::Target *parent) const;
 };
 
 } // namespace Internal