ENH: avoid references to temporaries in surfaceWriter

- previously wrapped raw points/faces with a meshedSurfRef on input,
  but now handle the raw -> meshedSurf logic directly within
  surfaceWriter to avoid holding references to temporaries

  Since the updated meshedSurfRef is now modifiable, it can be used
  directly as a redirection mechanism within surfaceWriter.

- add explicit close() in destructor