Merge pull request #614 from aws-lumberyard-dev/Atom/mnaumov/ATOM-15474

[ATOM-15474] Material Editor camera controller zoom respects viewport boundary

Code/Framework/AzToolsFramework/AzToolsFramework/Viewport/ViewportMessages.h

@@ -244,6 +244,8 @@ namespace AzToolsFramework
             /// from ViewportCursorScreenPosition. This method will always return the correct position to generate a mouse
             /// position delta.
             virtual AZStd::optional<AzFramework::ScreenPoint> PreviousViewportCursorScreenPosition() = 0;
+            /// Is mouse over viewport.
+            virtual bool IsMouseOver() const = 0;
 
         protected:
             ~ViewportMouseCursorRequests() = default;