feat: first version of OmniRelayer

[frolvanya]

NEAR -> ETH

• [x] Tracking NEAR events and filtering out events with ft_on_transfer call
  • [x] Filter out sign_transfer_callback calls as well to retreive logs
• [x] Sign transaction on relayer's behalf
• [x] Call finalize_deposit_omni method using bridge-sdk

ETH -> NEAR

• [x] Track withdraw events on eth blockchain
  • Side note: current rpc provider doesn't support eth_newFilter method, therefore we can't watch for incomming logs. As far as I understood, it can be fixed by switching to infura rpc provider
• [x] Call finalize_withdraw method using bridge-sdk

Other

• [x] Claim fee (I can't debug it for now, because omni_deposit doesn't exist yet)
• [x] Check if given fee is greater than expected fee (I've done simple implementation, but it needs to be modified later)
  • [x] Calculate fee on sender chain in native tokens
  • [x] Calculate fee on receiver chain in native tokens
  • [x] Using current exchange rate compare fee in USDT Possible problems:
  • Some tokens don't have a price (e.g coingecko is giving "0" as a price for those tokens)
  • Some tokens have a "fake" price (you can't actually exchange them using given price) Possible solutions:
  • To have a whitelist of "good" tokens that can be transferred using omni-bridge
• [ ] Wormhole integration

closes #5

[frolvanya]

@karim-en How much data should be stored in redis db? Should we set an expiration time for each log (e.g 1 day) or configure a simple log rotation (e.g keep only last 1000 logs)?