Memoize `getScriptsHashesNeeded` for subtransactions in Dijkstra era

[lehins]

getScriptsHashesNeeded isn't completely free, since it iterates over scriptsNeeded and constructs a Set of all hashes.
It so happens that this conversion is called twice for all subtransactions:

• once in SUBUTXOW
• and another in UTXOW

It will make sense to memoize this computation by adding a field to DijkstraStAnnSubTx:

    , dsastScriptsHashesNeeded :: Set ScriptHash

and using it instead in those rules.

That will also require addition to DijkstraEreUTxO of this new accessor:

  scriptsHashesNeededStAnnTx :: StAnnTx SubTx era -> Set ScriptHash