Add support for hardhat + ethers v6

[fvictorio]

I'm working on a new version of the hardhat-ethers plugin and I want to make sure that it works well with typechain. From what I can see, typechain's hardhat plugin hasn't been updated yet (which makes sense, because we haven't updated our plugin 😅).

Some comments from looking at the codebase:

• The version of ethers used in @typechain/hardhat should be updated, and the dependency on @typechain/ethers-v5 should be replaced with @typechain/ethers-v6
• I think some peer dependencies (@ethersproject/abi and @ethersproject/providers) in @typechain/hardhat could be dependencies. This is no strictly necessary, but reducing peer dependencies prevents conflicts down the road.
• codegen/hardhat.ts in @typechain/target-ethers-v6 will need to be updated. Here I think we'll have to coordinate, but at the very least:
  • The new version of the plugin will be called @nomicfoundation/hardhat-ethers, not @nomiclabs.
  • getContractAt will also accept an Addressable as the address, so those types should be changed to string | Addressable.

I'll be working on this today and I'll comment here anything else I find.

[fvictorio]

Some other things that need to be done.

In @typechain/hardhat:

• Change the default target in the config to ethers-v6

In @typechain/ethers-v6:

• Add generated typings for deployContract
• Change ethers.utils.BytesLike to ethers.BytesLike

I think these changes should be enough. This would mean though that the next major version of @typechain/hardhat uses ethers v6 by default. The alternative is to release a separate plugin for v6... but I don't think that makes sense here.