2.0.7: Deploy BalanceHelpers on Rootstock mainnet and testnet (#144)

* Deploy balanceHelper contracts on rootstockTestnet
* Deployed contracts on testnet and mainnet
- Deployed all v1 contracts on Rootstock Testnet and `BalanceHelper` and `BalanceHelperV2` on Rootstock Mainnet.
- Added chain configs for Rootstock Mainnet.
- Added `balanceHelpers` tag on deployment script to make it easier to solely deploy balance helper contracts.
-Upgraded hardhat-etherscan package to later version.
* Fix test issue and bump package version
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Co-authored-by: Luke Wickens <lukewickens1989@gmail.com>