Rework session initialization to return to the Qt event loop while connecting

We also display multiple launch warnings at the same time

app/streaming/session.h

@@ -1,7 +1,7 @@
 #pragma once
 
 #include <QSemaphore>
-#include <QWindow>
+#include <QQuickWindow>
 
 #include <Limelight.h>
 #include <opus_multistream.h>
@@ -96,13 +96,14 @@ class Session : public QObject
     friend class SdlInputHandler;
     friend class DeferredSessionCleanupTask;
     friend class AsyncConnectionStartThread;
-    friend class ExecThread;
 
 public:
     explicit Session(NvComputer* computer, NvApp& app, StreamingPreferences *preferences = nullptr);
     virtual ~Session();
 
-    Q_INVOKABLE void exec(QWindow* qtWindow);
+    Q_INVOKABLE bool initialize(QQuickWindow* qtWindow);
+    Q_INVOKABLE void start();
+    Q_PROPERTY(QStringList launchWarnings MEMBER m_LaunchWarnings NOTIFY launchWarningsChanged);
 
     static
     void getDecoderInfo(SDL_Window* window,
@@ -132,8 +133,6 @@ signals:
 
     void displayLaunchError(QString text);
 
-    void displayLaunchWarning(QString text);
-
     void quitStarting();
 
     void sessionFinished(int portTestResult);
@@ -141,10 +140,10 @@ signals:
     // Emitted after sessionFinished() when the session is ready to be destroyed
     void readyForDeletion();
 
-private:
-    void execInternal();
+    void launchWarningsChanged();
 
-    bool initialize();
+private:
+    void exec();
 
     bool startConnectionAsync();
 
@@ -256,13 +255,12 @@ private:
     bool m_AudioDisabled;
     bool m_AudioMuted;
     Uint32 m_FullScreenFlag;
-    QWindow* m_QtWindow;
-    bool m_ThreadedExec;
+    QQuickWindow* m_QtWindow;
     bool m_UnexpectedTermination;
     SdlInputHandler* m_InputHandler;
     int m_MouseEmulationRefCount;
     int m_FlushingWindowEventsRef;
-    QList<QString> m_LaunchWarnings;
+    QStringList m_LaunchWarnings;
     bool m_ShouldExitAfterQuit;
 
     bool m_AsyncConnectionSuccess;