Don't render extension methods and apply on typedef void* types

[keynmol]

For example, we currently render typedef void* mu_Font as

opaque type mu_Font = Ptr[Byte]
  object mu_Font: 
    given _tag: Tag[mu_Font] = Tag.Ptr(Tag.Byte)
    inline def apply(inline o: Ptr[Byte]): mu_Font = o
    extension (v: mu_Font)
      inline def value: Ptr[Byte] = v

Whereas for the particular case of void* we should be rendering extension methods or apply.