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/CryEdit.cpp

@@ -95,7 +95,6 @@ AZ_POP_DISABLE_WARNING
 #include "Core/QtEditorApplication.h"
 #include "StringDlg.h"
 #include "NewLevelDialog.h"
-#include "GridSettingsDialog.h"
 #include "LayoutConfigDialog.h"
 #include "ViewManager.h"
 #include "FileTypeUtils.h"
@@ -400,7 +399,6 @@ void CCryEditApp::RegisterActionHandlers()
 
     ON_COMMAND(ID_WIREFRAME, OnWireframe)
 
-    ON_COMMAND(ID_VIEW_GRIDSETTINGS, OnViewGridsettings)
     ON_COMMAND(ID_VIEW_CONFIGURELAYOUT, OnViewConfigureLayout)
 
     ON_COMMAND(IDC_SELECTION, OnDummyCommand)
@@ -3459,14 +3457,6 @@ void CCryEditApp::OnUpdateWireframe(QAction* action)
     action->setChecked(nWireframe == R_WIREFRAME_MODE);
 }
 
-
-//////////////////////////////////////////////////////////////////////////
-void CCryEditApp::OnViewGridsettings()
-{
-    CGridSettingsDialog dlg;
-    dlg.exec();
-}
-
 //////////////////////////////////////////////////////////////////////////
 void CCryEditApp::OnViewConfigureLayout()
 {