use thegraph as primary data source for farm page for performance, with fallback to rpc like now

[kasumi-1]

Is your feature request related to a problem? Please describe.
Originally this page used thegraph so I had to make new rpc thing for it to get data. This adds a delay, but will always work (presuming rpc works).

Describe the solution you'd like
Re-enable thegraph farm data grabber, and if there is some issue with thegraph be able to fallback to rpc. This would get us best of both worlds of speed + reliability.

[kasumi-1]

$300 MIST bounty (check #bounties in https://discord.gg/mistswapdex) - please write CLAIM here and submit PR within 3 days of claiming - if task is not completed within 3 days of claiming another user may claim to finish.

[mainnet-pat]

claim