[CDEC-304] Remove field accessors from `MerkleNode a`
[CDEC-304] Remove field accessors from `MerkleNode a`

input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype