we were calling llarp::Context::HandleSignal from a non mainloop
thread when running as a win32 service. this caused issues with a non
clean destruction.
call our signal handler instead of llarp::Context::HandleSignal
If wintun fails it seems to take about 15s, so extend the startup
timeout so that it can fail gracefully (and let us clean up before
exiting).
Also refactors the timeouts to chrono constants.
Fixes windows shutdown crashes:
- windivert wasn't handling an ERROR_NO_DATA, which it gets when
finished handling everything after a shutdown.
- wintun ReadPacket still gets invoked after end_session is called, but
shouldn't be. This adds an atomic<bool> to early return.
- fixes up some settings we send for windows service manager notify
the win32 and sd_notify components provided a disjointed set of
similar high level functionality so we consolidate these duplicate
code paths into one that has the same lifecycle regardless of platform
to reduce complexity of this feature.
this new component is responsible for reporting state changes to the
system layer and optionally propagating state change to lokinet
requested by the system layer (used by windows service).
