[TW-148] show instance ClassifiedNode
[TW-148] show instance ClassifiedNode

Also removed a redundant constraint on asOutboundQueue.

input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,serokell/tw-rework-sketch