Multi chain price oracles

Coingekko now supports tickers for lots of chains.

If you use this API:

```https://api.coingecko.com/api/v3/simple/token_price/[chain name]?contract_addresses=[list of CSV token addresses] &vs_currencies=USD&include_24hr_change=true";```

You can replace the [chain name] with any of these:

```
1 - "ethereum"
100 - "xdai"
56 - "binance-smart-chain"
137 - "polygon-pos"
61 - "ethereum-classic"
250 - "fantom"
43114 - "avalanche"
128 - "huobi-token" (HECO)
```