Integrate Multichain Gas Relayer

[bh2smith]

Near is building a multchain gas relayer service see example docs:
https://docs.near.org/build/chain-abstraction/multichain-gas-relayer/relayer-gas-example

However, getting setup is quite lengthy. We would ideally be able to integrate a route for users to opt in or out of relayer services (depending if they have a funded EVM account, or would prefer to pay all their tx/gas fees in Near).

There are many software components involved in running the relayer services that need to tweaks before this will work. Below are a list of relevant references:

• Relayer Server 🦀:
  https://github.com/near/multichain-relayer-server
• Event Indexer 🐍:
  https://github.com/near/gas-station-event-indexer
• Gas Station Contracts 🦀:
  https://github.com/near/multichain-gas-station-contract

Updated Instructions can be found in this GIST:
https://gist.github.com/bh2smith/0ed1dfb405e65277a148408c1442a229

Still having issues with relaying paymaster transactions and having them mined...

Example: 0xdc835a21b84f3c40b8819ca07ca6c442b4a5a630c74f77878d712dfae68f3334

Was posted but never mined...

[bh2smith]

Very subtle thing to note that the gas contract has changed to v2.nft.kagi.testnet