Spectation: add dedicated pathway for spectator mode (#5303)

* Spectation: add dedicated pathway for spectator mode

+ Sync player rotation with spectated entity.
+ Add dedicated infrastructure to cPlayer for handling spectation, instead of misusing entity riding.
* Avoid infinite recursion when exiting spectation, fixes #5296

* AttachTo: Change parameter to reference

tests/Generating/Stubs.cpp

@@ -696,7 +696,7 @@ void cEntity::BroadcastMovementUpdate(class cClientHandle const * a_ClientHandle
 
 
 
-void cEntity::AttachTo(class cEntity * a_Entity)
+void cEntity::AttachTo(class cEntity & a_Entity)
 {
 }
 
@@ -766,6 +766,15 @@ void cEntity::ResetPosition(class Vector3<double> a_Pos)
 
 
 
+void cEntity::OnDetach()
+{
+
+}
+
+
+
+
+
 cPawn::cPawn(enum cEntity::eEntityType, float a_Width, float a_Height) :
 	cEntity(etMonster, Vector3d(), a_Height, a_Width)
 {