ProjectExplorer: Run RunControl::{start,stop} always asynchronously

This introduces a mini-state-"machine" to handle RunControl states
Intialized->[Starting->Running->Stopping->Stopped->]*->Finished.

Needing time between trying to start and getting feedback is nowadays
the normal setup for all remote targets as well as for most local tools.
Making that the default for all runs simplifies the code and provides an
opportunity to (a) fix some currently wrong reports of "stopped
immediately" and (b) to remove target-specific (WinRT) or tool-specific
(Valgrind, GammaRay) state members doing essentially the same.

Change-Id: I7f52fee41144188ee8389e922fdc265f8c0a6459
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/qmlprofiler/qmlprofilerruncontrol.h

@@ -48,7 +48,7 @@ public:
     void notifyRemoteSetupDone(Utils::Port port) override;
     void notifyRemoteSetupFailed(const QString &errorMessage) override;
     void start() override;
-    StopResult stop() override;
+    void stop() override;
     void cancelProcess();
     void notifyRemoteFinished() override;
     bool supportsReRunning() const override { return false; }