* Make some startup procedures async.
Add more handful makeBannerAndConfig().
* Dissect windows service code from `nimbus_beacon_node.nim`.
* Add report service startup errors using windows error codes.
Add plug able exitService().
Co-authored-by: Zahary Karadjov <zahary@status.im>
Co-authored-by: Jacek Sieka <jacek@status.im>