[PB-26] Reuse transaction output in tx generator
[PB-26] Reuse transaction output in tx generator

In case constructing the addresses and outputs is what makes the
generator CPU bound.

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