Necessary alerts from bridge relayer

[shaspitz]

We need to invoke slack alerts from the bridge relayer service for the following conditions

• The bridge relayer should have at least 1 ETH on L1 at any given time, and alert if balance becomes below 1 eth -> https://etherscan.io/address/0xf0E4285D437Be60975149d5cac2DeA49756a238B
• Each bridge gateway's finalizationFee must be set higher than finalization tx cost for that chain. We need to monitor the diff between finalzationFee and actual tx cost. If the diff is too large, our team would be required to change the finalizationFees on-chain, hence slack alert is needed