Remove all references to old CGrid system (#672)

* add overload to ActionManager to support capturing an AZStd::function

* move snapping settings to new settings registry

* remove unneeded reference in ViewportSettings

* move viewport setting function implementations to .cpp file

* add more sensible default values for snapping

* fix variable name for angle snapping

* remove const from function prototype value parameters

* add import/export api for free functions

* change from std::bind to a lambda

* remove redundant const for constexpr string_view

* add AZStd alias for std::abs

* restore grid and angle snapping

* add overload to ActionManager to support capturing an AZStd::function

* remove old legacy CGrid code

* fix build after merge

* review feedback changes - remove 1.0f multiplies

Code/Sandbox/Editor/ViewManager.h

@@ -20,7 +20,6 @@
 #pragma once
 
 #include "Cry_Geo.h"
-#include "Grid.h"
 #include "Viewport.h"
 #include "Include/IViewPane.h"
 #include "QtViewPaneManager.h"
@@ -67,10 +66,6 @@ public:
     void SetUpdateRegion(const AABB& updateRegion) { m_updateRegion = updateRegion; };
     const AABB& GetUpdateRegion() { return m_updateRegion; };
 
-    /** Retrieve Grid used for viewes.
-    */
-    CGrid* GetGrid() { return &m_grid; };
-
     /** Get 2D viewports origin.
     */
     Vec3 GetOrigin2D() const { return m_origin2D; }
@@ -137,7 +132,6 @@ private:
     AZ_PUSH_DISABLE_DLL_EXPORT_MEMBER_WARNING
     AABB m_updateRegion;
 
-    CGrid m_grid;
     //! Origin of 2d viewports.
     Vec3 m_origin2D;
     //! Zoom of 2d viewports.