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/Objects/BaseObject.cpp

@@ -1268,12 +1268,6 @@ int CBaseObject::MouseCreateCallback(CViewport* view, EMouseEvent event, QPoint&
     if (event == eMouseWheel)
     {
         double angle = 1;
-
-        if (view->GetViewManager()->GetGrid()->IsAngleSnapEnabled())
-        {
-            angle = view->GetViewManager()->GetGrid()->GetAngleSnap();
-        }
-
         Quat rot = GetRotation();
         rot.SetRotationXYZ(Ang3(0, 0, rot.GetRotZ() + DEG2RAD(flags > 0 ? angle * (-1) : angle)));
         SetRotation(rot);