Refactor duplicate code

[mrosendin]

Balances component has this:

import FLR from "../../assets/flr.jpg"
import SGB from "../../assets/sgb.png"
import USD from "../../assets/usd.png"
import XRP from "../../assets/xrp.png"
import ETH from "../../assets/eth.png"
import AssetContext from "../../contexts/AssetContext"

const assetIcons: { [key: string]: string } = {
  CFLR: FLR,
  SGB,
  FLR,
  USD,
  XRP,
  ETH
}

AssetSelector component has this:

import ETH from "../../assets/eth.png"
import FLR from "../../assets/flr.jpg"
import SGB from "../../assets/sgb.png"
import USD from "../../assets/usd.png"
import XRP from "../../assets/xrp.png"
import AssetContext from "../../contexts/AssetContext"

const IMAGES: { [key: string]: any } = {
  "FLR": FLR,
  "SGB": SGB,
  "CFLR": FLR,
  "XRP": XRP,
  "ETH": ETH
}

This should be moved into one common file