Address clang tidy complaints

Update Ghoul repository
Update SGCT repository

include/openspace/rendering/dashboard.h

@@ -28,6 +28,7 @@
 #include <openspace/properties/propertyowner.h>
 
 #include <openspace/properties/scalar/boolproperty.h>
+#include <openspace/rendering/dashboarditem.h>
 #include <ghoul/glm.h>
 #include <memory>
 #include <vector>
@@ -36,12 +37,10 @@ namespace openspace {
 
 namespace scripting { struct LuaLibrary; }
 
-class DashboardItem;
-
 class Dashboard : public properties::PropertyOwner {
 public:
     Dashboard();
-    ~Dashboard();
+    ~Dashboard() = default;
 
     void render(glm::vec2& penPosition);
 

include/openspace/rendering/loadingscreen.h

@@ -68,6 +68,7 @@ public:
     void tickItem();
 
     enum class Phase {
+        PreStart,
         Construction,
         Synchronization,
         Initialization
@@ -97,7 +98,7 @@ private:
     bool _showNodeNames;
     bool _showProgressbar;
 
-    Phase _phase;
+    Phase _phase = Phase::PreStart;
     std::atomic_int _iProgress = 0;
     std::atomic_int _nItems = 0;