Added "Export Scene" in the scenes right click context menu

I have added a "Export Scene" menu item to the scenes right click context menu below "Copy".

When hovered over it will open a sub-menu where the user can then select the scene collection file the user wants to export the selected scene to then a dialog will open telling the user the export was successful or the scene already exists in the selected scene collection.

I believe this is useful for users that want to copy or move scenes to a different scene collection.