feat: LP V2 message forwarding

[wischli]

Description

Adds feature to handle forwarding inbound and outbound messages

• Adds new pallet pallet-liquidity-pools-forwarder which implements MessageReceiver and MessageSender
• Adds new runtime type MessageSerializer which acts as entity to serialize and deserialze all incoming and outgoing messages
• Instantiates router mock
• Removes extrinsic receive_message from Gateway since this was only used by the axelar router
  • If it is necessary in the future, should be added to router instead

In order to set up forwarding for some Domain::Evm(123)

1. In pallet-liquidity-pools-forwarder storage RouterForwarding: Store the source_domain and forwarding contract address for some router_id
2. In pallet-liquidity-pools-gateway storage Allowlist: Store the (source_domain, DomainAddress::Evm(source_somain, forwarding_contract_address)

Sending messages

Before this PR

Gateway -> RouterDispatcher -> Router

After this PR

Gateway -> Forwarder -> Serializer -> RouterDispatcher -> Router

Receiving messages

Before this PR*

Router -> Gateway

After this PR

Router -> Serializer -> Forwarder -> Gateway

TODO

• [x] Refactor MessageEntry and InboundEntry to use Domain instead of DomainAddress
• [x] Wire into runtimes and with other pallets
• [x] Unit tests
• [x] Add docs
• [x] Fix Domain and SerializableDomain ATs of LpMessage
• [x] Move (de-)serialization to runtime type MessageSerializer

Checklist:

• [x] I have added Rust doc comments to structs, enums, traits and functions
• [x] I have made corresponding changes to the documentation
• [x] I have performed a self-review of my code
• [x] I have added tests that prove my fix is effective or that my feature works

[lemunozm]

Just a NIT thought. Seems like an entity called forwarder is not the entity in charge of serializing / deserializing, could be weird to find those methods here? 🤔

Could make sense a super thing wrapper as a type runtime that makes that serialization?

// To send
gateway -> forwarder -> serializer -> router-dispatcher -> router 

// To receive
router -> serializer -> forwarder -> gateway

The serializer could be just a MessageSerializer implementing MessageSender and MessageReceiver type who calls msg.serialize() and deserialize().

Just a thought, and maybe being a paranoic organizer 😆

[wischli]

Just a NIT thought. Seems like an entity called forwarder is not the entity in charge of serializing / deserializing, could be weird to find those methods here? 🤔

Could make sense a super thing wrapper as a type runtime that makes that serialization?

// To send

gateway -> forwarder -> serializer -> router-dispatcher -> router 

// To receive

router -> serializer -> forwarder -> gateway

The serializer could be just a MessageSerializer implementing MessageSender and MessageReceiver type who calls msg.serialize() and deserialize().

Just a thought, and maybe being a paranoic organizer 😆

I agree that your proposal would be the preferred design. Will look into it later after finishing the mandatory tasks for this feature.

[lemunozm]

Great! but please, it is not mandatory at all for Monday 🙏🏻

[wischli]

Great! but please, it is not mandatory at all for Monday 🙏🏻

Much cleaner now: b39fa47

[cdamian]

Only a couple of minor nits, I'm happy we got to slay this one as well, thank you @wischli!

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 56.00000% with 33 lines in your changes missing coverage. Please review.

Project coverage is 49.01%. Comparing base (03262c5) to head (5cf3752).

Files	Patch %	Lines
pallets/liquidity-pools/src/message.rs	0.00%	21 Missing :warning:
runtime/common/src/routing.rs	0.00%	6 Missing :warning:
pallets/liquidity-pools-forwarder/src/lib.rs	92.30%	3 Missing :warning:
runtime/altair/src/lib.rs	0.00%	1 Missing :warning:
runtime/centrifuge/src/lib.rs	0.00%	1 Missing :warning:
runtime/development/src/lib.rs	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1971 +/- ## ========================================== + Coverage 48.92% 49.01% +0.09% ========================================== Files 183 184 +1 Lines 13133 13200 +67 ========================================== + Hits 6425 6470 +45 - Misses 6708 6730 +22 ```

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[wischli]

Thanks @wischli for bringing this super PR along with documentation chains so fast!! 🚀 I really like the result.

Just few NITs, some questions, and just one think that I would simplify about mocking the Message in both pallets.

But the code looks super great! Thanks

Absolutely agree! Sorry I didn't initiate like that but prio was to get it done. If you think, you can still fit something in, great, but entirely optional. Whatever we change might have to be updated/added to the docs.