Add a --log-local-time flag that configures cloudflared to use local
timezone for log timestamps instead of the default UTC.
This helps users correlate logs with local system events and other
services running in their timezone.
The flag can also be set via the TUNNEL_LOG_LOCAL_TIME environment
variable.
Closes#1530
By default, we want streaming logs to be able to stream debug logs
from cloudflared without needing to update the remote cloudflared's
configuration. This disconnects the provided local log level sent
to console, file, etc. from the level that management tunnel will
utilize via requested filters.
This addresses a bug where logging would not be output when
cloudflared was run as a Windows Service.
That was happening because Windows Services have no stderr/out,
and the ConsoleWriter log was failing inside zerolog, which would
then not proceed to the next logger (the file logger).
We now overcome that by using our own multi writer that is resilient
to errors.