E2E L1 -> L2

[LHerskind]

For a full E2E of L1 to L2 messages, we need:

• circuits inserting L1 -> L2 msgs into tree
  • Add L1 -> L2 message tree #348
• acir simulator exposing msg tree
  • Add l1 -> l2 historic trees to acir simulator #521
• messageboxes deployed to l1
  • Build contract for input side of L1 -> L2 message box #517
  • Add registry and update rollup contract to consume/push message in boxes #523
• portal deployed to L1 (token bridge for start)
  • Token bridge portal contract (l1 native asset) #522
• archiver needs to pull L1 -> L2 msgs inserted
  • extend archiver to pull L1 -> L2 events from message box #520

Nice to haves:

• abi-like encoding in noir, to follow some of the best practices in https://docs.aztec.network/aztec/how-it-works/l1-l2-messaging#structure-of-messages

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L1 token bridge:

• Deploy token portal on L1 and L2, (specifying the L1 contract as portal for L2)
• Mint tokens on L1 (use mintable erc20 or weth)
• Initiate a deposit on L1 which will insert a message into the message box
• Archiver pulls events emitted on insertion
• Some other contract is deployed or interacted with and the sequencer includes this message in the rollup
  • After rollup, the message is inserted into the messages tree
• User initiate L2 "deposit" which consumes the message from the tree and mints tokens on L2.