drop dependencies from dmap.js

[nmushegian]

ethers

• ethers.utils.defaultAbiCoder
• • we only need to encode one call, get
• ethers.utils.keccak256
• • find a standalone implementation
• ethers.utils.hexZeroPad
• • just extract this function
• ethers.BigNumber.from
• • use native BigInteger
• ethers.utils.Interface
• • pretty sure lib.slot is deprecated now?

ebnf

• the parser for dpath should be trivial

[dmfxyz]

• ethers.utils.keccak256: We can use https://www.npmjs.com/package/keccak, or do we prefer to write our own implementation from scratch?

• ethers.utils.defaultAbiCoder should be able to write this ourselves for the basic encode call. Would like to keep ethers around to differentially test though, at least at the start.

• ethers.utils.hexZeroPad ack on extraction

• ethers.BigNumber.from ack on using native

Have to look into lib.slot more to make sure I fully understand how it's being used.