feat: daily bridge transfer limits

[maharifu]

Related Github tickets

• Closes [Pigeon Feed] As a user, I want Pigeon to set a daily Bridge Limit for token transfers across the bridge to the target EVM chain VolumeFi/paloma#1711

Background

Add a limit to the amount of tokens transferred out from paloma within a specified window, per token. This is defined by a new governance vote.

• Add governance vote. Can define token, window size, token limit and list of exempt addresses.
• Keep a counter of the number of tokens transferred and the block height at the start of the limiting window.
• Before accepting a transfer, update the counters and check the limits.
• Transfers are refused if over the transfer limit.

Testing completed

• test coverage exists or has been added/updated
• tested in a private testnet

Breaking changes

• I have checked my code for breaking changes
• If there are breaking changes, there is a supporting migration.

[maharifu]

@taariq @byte-bandit I assumed we want to update/check the counters when adding the transfer to the queue, and will not decrease the counters even if the transfer fails or is cancelled afterwards.

[taariq]

@maharifu correct. No need to decrease the counters on cancellation. All good.

[taariq]

@byte-bandit your review? Let's merge this in!

[byte-bandit]

Good stuff. Some small input, but non-blocking. Up to you.