Wrapper tx replay protection

[tzemanovic]

As noted in https://github.com/anoma/anoma/blob/625bab46c32da6aeb35418869974bfb1ac98cd3e/docs/src/specs/ledger.md: "DKG transactions will include replay protection (this is because we can simply check a counter against the source (i.e. gas payer) of the transaction before the transactions order is committed to by the DKG protocol, which could affect the expected counter order for sources with multiple queued transactions)".

We should add reply protection to the wrapper tx. This can simply be a counter in implicit accounts that is checked and incremented by the wrapper transactions.

┆Issue is synchronized with this Asana task by Unito

[tzemanovic]

The replay protection should probably be implemented in the protocol as it doesn't need to involve any VP. The counter field should then be added to the wrapper tx. For a tx to be valid, it should match the current value of the counter stored for the source implicit account in the ledger. To submit multiple txs from the same account at once, we should allow to explicitly set the --counter for any tx. If not specified, the client can read (default to 0, if no counter is set yet) and use the current value from the ledger.

[tzemanovic]

with anoma/anoma#676, it should be possible to auto-increment the counter so the user never has to specify it explicitly

[batconjurer]

So after some discussion, we came to the following idea:

• In each the storage addressed to each implicit account, we keep a counter.
• Wrapper txs will now include a counter field
• During process proposal, we check in the wrapper txs that the counter field is >= than the counter in storage.
• During finalize block, in the write ahead log, for each tx, we take the max of the new counter for the associated implicit acount and the tx counter field.

[grarco]

Closed in favor of #1009