Merge #14335: net: refactor: cleanup ThreadSocketHandler

032488e Move SocketHandler logic to private method. (Patrick Strateman)
2af9cff Move InactivityCheck logic to private method. (Patrick Strateman)
7479b63 Move DisconnectNodes logic to private method. (Patrick Strateman)
edb5350 Move NotifyNumConnectionsChanged logic to private method. (Patrick Strateman)

Pull request description:

  Working towards using poll() on unix like systems.

  A number of small changes designed to separate the actual socket handling from the rest of the logic in ThreadSocketHandler.

  This is a simpler version of #14147

Tree-SHA512: 72f35c8ef7649019dcbfe19537d8c9f7e3d0fc5854dc691a70c5573352230fc31c3f55565820c632e9b8cb3c55b878bed19e0ad9423100762197ac35967d8067

Author: laanwj