Who is the narrator of "The Happy Prince" by Oscar Wilde?

The narrator is a third-person omniscient narrator who hovers "over" the action of the story, telling us what happens. An omniscient narrator is all seeing. This narrator is so all seeing that he even knows what happens in heaven.
Much of the story is told from the point of view of the swallow, but the third-person omniscient narrator offers us the background of how people admire the statue of the prince before the swallow appears. The narrator also provides information on what happens to the swallow after the swallow has died.
The third-person narrator is an anchor who can tell readers what they need to know as the story unfolds. The narrator also helps guide readers toward understanding the moral of the story. After the swallow's death and the "death" of the happy prince statue through being melted down, we learn that God values the good deeds those two did for the poor more anything else in the city. We know this because the omniscient narrator informs us of the following, which only he could know:

“Bring me the two most precious things in the city,” said God to one of His Angels; and the Angel brought Him the leaden heart and the dead bird.
“You have rightly chosen,” said God, “for in my garden of Paradise this little bird shall sing for evermore, and in my city of gold the Happy Prince shall praise me.”