feat(HypercoreDepositHandler): Allow different types of messages passed to handleAcrossV3Message

[nicholaspai]

Read first byte to determine how to decode message:

• type 1: message = abi.encode(user)
• type 2: message = abi.encode(user, signature)

type 2 messages can be used to activate new accounts, type 1 cannot

[grasphoper]

@nicholaspai are we moving forward with sig-based account creation? As we discussed in Slack, this doesn't fully protect us from griefing, but makes griefing a bit harder

[nicholaspai]

@nicholaspai are we moving forward with sig-based account creation? As we discussed in Slack, this doesn't fully protect us from griefing, but makes griefing a bit harder

Yes, because we want the griefing protection to be possible at the API level. With signatures we can control do this, whereas if we don't have signatures at all, then even the API can't protect against this.

[grasphoper]

@nicholaspai are we moving forward with sig-based account creation? As we discussed in Slack, this doesn't fully protect us from griefing, but makes griefing a bit harder

Yes, because we want the griefing protection to be possible at the API level. With signatures we can control do this, whereas if we don't have signatures at all, then even the API can't protect against this.

Oh, you mean that the API can block by IP and such?