feat: test utils and abi code generator

[fubhy]

Done:

• [x] Generate typescript classes for ethers.js
• [x] Add ethers.js providers and signers using ganache state
• [x] Add ganache provider with access to ganache state trie for send / call assertions
• [x] Add utils for test fixtures (fund setup, etc.)

Next up (follow up):

• [x] Add assert utils for events
• [x] Add assert utils for send / call code paths (unit tests)
• [x] Add better matchers for big number, etc.

... More to be added

[fubhy]

@SeanJCasey Let's merge this <3