Simple pretty printer for netencode values, as a rust library and an
accompanying command line tool which takes netencode on stdin and
prints the pretty version to stdout.
Change-Id: I0a57c644985162bc08a9bf1ee78f7be278400199
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2532
Tested-by: BuildkiteCI
Reviewed-by: Profpatsch <mail@profpatsch.de>