Add registry and update rollup contract to consume/push message in boxes

[LHerskind]

Add the registry that keeps track of the message boxes and the rollup.

Must also update the rollup contract to allow consumption of messages from the L1 -> L2 message box contract if they are part of the L2 block. And likewise inserting messages into the contract for L2 -> L1 message box.

For the circuit side related to Add L1 -> L2 message tree and Propagate L2 -> L1 messages which will alter the public inputs hash.