ProjectExplorer: Consolidate RunConfigurationFactory::ids

It was already only one id string with two names. Since it is not
an id for the factory but the id of the created run configuration,
settle of  runConfigurationId() as accessor.

The factory and id fields in RunConfigurationCreationInfo were
redundant. factory always implies (runconfiguration)id (but not
necessarily the other way round, in theory different factories
are possible for the same runconfiguration type for different
devices). So drop the id field here.

In one case now factory pointers instead of ids are compared, but
this is neutral there as this happens in a context of a fixed Target,
device and project are fixed there, so id and factory are equally
unique.

Change-Id: I859aa91486a2dd4abfc7369540a3322d6ec6260d
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/qmlprojectmanager/qmlprojectplugin.cpp

@@ -47,7 +47,7 @@ public:
     RunWorkerFactory runWorkerFactory{
         RunWorkerFactory::make<SimpleTargetRunner>(),
         {ProjectExplorer::Constants::NORMAL_RUN_MODE},
-        {runConfigFactory.id()}
+        {runConfigFactory.runConfigurationId()}
     };
 };