Removing ethers from the dependencies

[alcuadrado]

As we discussed yesterday, having ethers as a dependency in web3.js makes npm stats worthless, and we should remove it asap.

I'm inclined to vendor the part of ethers that web3 uses for now, as it's a low effort way of solving it, release a patch version, and then analyze if an ethers v5 package can be used.

As I already mentioned, keep in mind that a change like this one takes some time to manifest itself in the stats, so releasing soon is pretty important.

[ricmoo]

The package you will be interested in is @ethersproject/abi. There may be some issues revolving around invalid UTF-8 strings though. I can add a function similar to the coerceFunc to handle errors, so that errors can be recovered from, since I think web3 lets invalid data through. I'll tinker with ideas for this API.

[cgewecke]

cf: #3461 / #3441 / #1610

[ricmoo]

For discussion on the ABI Coder and possible solutions: ethers-io/ethers.js#800