[input-output-hk/cardano-sl] [CBR-97] structured logging (#3401)

erikd commented on this pull request.

> return False
when b $ liftIO (withMVar v $ \h -> (hPutStrLn h (encode event) >> hFlush h))
— `catchAny` \e ->
— logWarning $ sformat («can’t write json log: «%shown) e
+ `catchAny` \_ -> return ()
+ —logWarning logTrace $ sformat («can’t write json log: «%shown) e

Commented out code.