Switch sd_event loops to sdeventplus

This change is mostly focused around plumbing the sdeventplus::Event
object everywhere and using the member functions provided for the event.
No migration to the timer utility is performed yet.

Change-Id: I912ab82bc081239d3b7c3cf7c5caca6742ef9c87
Signed-off-by: William A. Kennington III <wak@google.com>
24 files changed