code: def is_name_registered( self, name ):
          
          name_rec = self.get_name( name )    # won't return the name if expired
          if name_rec is None:
              return False 
  
          if name_rec['revoked']:
              return False
  
          return True
docs: Given the fully-qualified name, is it registered, not revoked, and not expired
          at the current block?