net: refactor self=this to arrow functions

Affected core subsystem(s)

net

Description of change

Refactor unused self=this code to code without without this pattern making it more consistent with the rest of our code.

There were PRs to do this code-base wide but they all seem to have stalled so I figured I'd do this in the least objectionable way one change at a time.

CI: https://ci.nodejs.org/job/node-test-pull-request/2037/console