AP-786 Strategy Cleanup

[stevieraykatz]

Explanation of the solution

This PR encapsulates two changes that are blocking for strategy development and flux deployment:

Refactor
I found that the Flux implementation was duplicating a lot of generic strategy-specific logic and genercized it further and moved it into APStrategy_V1. This part of the PR should be a no-op change, just a refactor.

Flux Strategy -> SafeERC20
I also changed the Flux strategy to using SafeERC20 instead of in-line approve/transfer checks. This should help with readability and gas. Additionally, I was using the Flux interface for interfacing with USDC. Though technically valid, that wasn't a good choice for readability... I'm not really sure why I made it in the first place. I've switched to using our standard IERC20 with SafeERC20 in its stead.

Instructions on making this work

• run yarn or yarn install to install npm dependencies

[linear]

AP-786 Deploy Flux Strategy

This involves a number of steps:

• Deploy a testnet strategy/vault pair
• Run deploySideChain on Ethereum mainnet
• Deploy the Flux strategy contracts
• Configure the registrars (see AP-638)