Fix the block explorer verification for ProxyFactory

[bbenligiray]

They used to work but they didn't work for the 2.1.0 release. Requires investigation.

[bbenligiray]

It was actually the ProxyFactory verification that was failing, rather than the proxies themselves. Furthermore, I think it has never worked to begin with.

hardhat-etherscan refers to the bytecode in artifacts/buildInfo/*.json for the compiled bytecode, so it doesn't even submit the respective source code to Etherscan because it can't get a good match with the on-chain bytecode. After applying the metadata replacement switch that I use after hardhat compile, it starts submitting the source code, yet Etherscan responds saying that the source code doesn't match the bytecode (even partially). Based on how hardhat-etherscan normalizes the bytecode, I think the problem is that Etherscan is not smart enough to ignore the metada differences in DapiProxy, DataFeedProxy, DapiProxyWithOev and DataFeedProxyWithOev. As a note, we have a similar situation with the AirseekerRegistry deployed by Api3Market, but that doesn't cause the same issue because we didn't make any changes that will cause AirseekerRegistry metadata mismatch.

The short term solution is to not verify ProxyFactory (so that the following contracts can be verified) f555551

There are two long term solutions:

• Create a separate branch where ProxyFactory (or rather, the proxies) can be built with the original metadata and verify ProxyFactory there
• Add a flattened version of the original ProxyFactory to the main branch and use that for verification (I made a brief attempt but couldn't make it work, though it shouldn't be that difficult)

[bbenligiray]

ProxyFactory will be supplanted by a new version soon, so won't fix