Who is the narrator of The Strange Case of Dr. Jekyll and Mr. Hyde?

This novella has a
third person omniscient narrator. This means that the narrator is
not a participant in the story's events and does not use the first person pronoun "I."
Omniscient means that the narrator knows the thoughts and feelings of all
of the characters, rather than none of them (which is called objective) or
one of them (which is called limited omniscient). For example, the narrator
tells us that Mr. Utterson

had an approved tolerance for
others; sometimes wondering, almost with envy, at the high pressure of spirits involved in their
misdeeds; and in any extremity inclined to help rather than to reprove.

If the narrator were not of the omniscient variety, he would not
be able to report on Mr. Utterson's private thoughts, such as these. Likewise, when the narrator
reports on the conversation between Mr. Utterson and Mr. Enfield, he says that Mr. Enfield
"fell into a vein of musing." Again, these are private thoughts, unspoken, to which an
objective third person narrator would not...