Identify as many components as possible that can be made DIRECT types

[Kelly Greco]

[Austin Littley]

I identified the following schedulers that could be direct

platformSchedulers.stateSigner,                      DIRECT
platformSchedulers.applicationTransactionPrehandler, DIRECT
platformSchedulers.hashLogger,                       DIRECT
platformSchedulers.signedStateSentinel,              DIRECT

We've decided not to move forward on this for now.