Pull log: log user for changes made using Dolt (like delete branch)

Make some doltremoteapi changes so we can log the user for changes made using dolt
If we want branch updates to be reflected in the pull activity log, we should get them reflected. On github, for example, I think the activity stream sometimes references who's pushing, instead of who the author of the commits are, for example.
If we thread pusher through the doltremoteapi -> dolthubapi interaction, we can always have a user on the dolthubapi side.