Remove I3DEngine CryCommon Interface (#567)

Delete:

- I3DEngine
- Missions
- Time of day
- GameEffectsSystem Gem
- ImageProcessing Gem
- SVOGI Gem
- Various other things that don't do anything now that the legacy renderer has been removed.

Code/CryEngine/CrySystem/System.h

@@ -408,13 +408,6 @@ public:
     virtual void DoWorkDuringOcclusionChecks();
     virtual bool NeedDoWorkDuringOcclusionChecks() { return m_bNeedDoWorkDuringOcclusionChecks; }
 
-    //! Begin rendering frame.
-    void    RenderBegin();
-    //! Render subsystems.
-    void    Render();
-    //! End rendering frame and swap back buffer.
-    void    RenderEnd(bool bRenderStats = true, bool bMainWindow = true);
-
     //Called when the renderer finishes rendering the scene
     void OnScene3DEnd() override;
 
@@ -429,11 +422,6 @@ public:
     //! Update screen and call some important tick functions during loading.
     void SynchronousLoadingTick(const char* pFunc, int line);
 
-    //! Renders the statistics; this is called from RenderEnd, but if the
-    //! Host application (Editor) doesn't employ the Render cycle in ISystem,
-    //! it may call this method to render the essential statistics
-    void RenderStatistics() override;
-
     uint32 GetUsedMemory();
 
     virtual void DumpMemoryUsageStatistics(bool bUseKB);
@@ -469,7 +457,6 @@ public:
     AZ::IO::IArchive* GetIPak() { return m_env.pCryPak; };
     IConsole* GetIConsole() { return m_env.pConsole; };
     IRemoteConsole* GetIRemoteConsole();
-    I3DEngine* GetI3DEngine(){ return m_env.p3DEngine; }
     IMovieSystem* GetIMovieSystem() { return m_env.pMovieSystem; };
     IMemoryManager* GetIMemoryManager(){ return m_pMemoryManager; }
     IThreadManager* GetIThreadManager() override {return m_env.pThreadManager; }
@@ -696,9 +683,6 @@ private:
     void CreateRendererVars(const SSystemInitParams& startupParams);
     void CreateSystemVars();
     void CreateAudioVars();
-    void RenderStats();
-    void RenderOverscanBorders();
-    void RenderMemStats();
 
     AZStd::unique_ptr<AZ::DynamicModuleHandle> LoadDLL(const char* dllName);