debt: use the single Etherscan V2 API endpoint for unified verification / query flow w/ single API key

[zerosnacks]

Component

Other (please describe)

Describe the feature you would like

We currently have a lot of code in place to handle multichain Etherscan verification due to the different endpoints and API keys associated with each.

With the release of Etherscan V2 there is now a single unified API endpoint: https://docs.etherscan.io/etherscan-v2 accessible with a single API key

Additional context

It is currently still in beta but worth exploring

Part of this ticket would be to double check if there are no breaking changes in the V2 API

Note: it requires passing a ?chainid=n as a parameter where n is the chain id: https://docs.etherscan.io/etherscan-v2/getting-started/v2-quickstart#if-youre-coming-from-v1

[iainnash]

Has this been started or would taking a first PR pass be helpful?

[zerosnacks]

Hi @iainnash, this is definitely something we will want to do, just outside of the scope of our 1.0 milestone due to scope of the change (I expect we can simplify quite a lot of code and likely make breaking changes). We also have to be mindful that the Etherscan API V2 is still in beta. A first PR pass to explore this would be very useful, even if it is just a draft!