feat(vaults): roi

[nymmrx]

Discussed in discord PMs.

Short summary:

• simplify ROI calculation in /vaults/all
• ~currently works only on V1 vaults~ Works with all vault versions (with the exception of Curve.fi GUSD/3Crv)
• /vaults/all now follows the format:

  [
  {
      "address": "0x29E240CFD7946BA20895a7a02eDb25C210f9f324",
      "type": "v1",
      "name": "yearn Aave Interest bearing LINK",
      "symbol": "yaLINK",
      "decimals": "18",
      "inceptionBlock": "10599617",
      "apy": {
          "oneMonth": 1.0058812208475776,
          "inception": 11.804965985152679
      }
  },
  {"..."}
  ]