[Prefabs] While Shapes hides MeshFilter/MeshRenderer, they show up in Prefab overrides

(raised as GitHub issue #32 first)

It's great that the MeshFilter/MeshRenderer components are hidden, but they still show up in the Prefab overrides menu.
This can be controlled via the component HideFlags; a specific combination of HideFlags (HideFlags.DontSave) does hide the changes from ever showing up in that Prefab Override window, reducing noise considerably.

Reporting a bug? please specify Unity version:
Reporting a bug? please specify Shapes version: