[WEB-1325-216] Add exporter pricing service

[jstashh]

• Clone the yearn exporter repo - https://github.com/yearn/yearn-exporter
• Checkout the branch feat/brownie_bridge
• Make sure these environment variables are set:

export WEB3_PROVIDER=...
export EXPLORER=...
export FTM_WEB3_PROVIDER=...
export FTM_EXPLORER=...

• run make bb-up
• wait for the bridge to finish starting up
• curl -X POST -H 'Content-Type: application/json' http://localhost:4004/v2/1/prices?type=json -d '["0x0bc529c00c6401aef6d220be8c6ea1667f6ad93e"]'

This endpoint fetches prices from yearn-exporter, it will eventually be hosted somewhere but it can be run locally for now for testing purposes. In this example we fetch the price just for YFI, but an array of tokens can be passed in.

A new service should be added to the SDK that fetches prices for all yearn tokens, caches the response for 3 minutes, and provides a function to fetch all prices, and one for individual prices. All yearn tokens can be found from the registry adapter's assetsTokensAddresses function - https://etherscan.io/address/0x240315db938d44bb124ae619f5fd0269a02d1271#readContract

[yearn-linear-gh-sync]

Linear reply from marius:
there's now an even simpler solution to this with yrpc:

Follow the above description and instead of curling the api endpoint at 4004 use this instead:

npm install https://github.com/mariuspod/yrpc.git

sample js client:

https://github.com/mariuspod/yrpc/blob/main/sample_client.js

[yearn-linear-gh-sync]

Linear reply from marius:
yearn/yearn-exporter#229

[pmdaly]

Working on this.