tls_wrap: return Error not throw for missing cert
test: use common.LineStream for line based tests
test: child-process-fork-net2 can finish in 180ms

Because we use uv_now for timers, setTimeout(fn, 200) is more accurate
than what Date.now resolution actually provides in context, so the test
was regularly completing faster than the wallclock of 190ms
test: increase time outs for racey tests

Getting the timing right for a child process to start debugging is
notoriously hard given the inflexibility of the protocol signalling
when it's ready.

Similarly a timeout of 100 may not be long enough for startup and
listen for some systems, especially windows