ApiClient fee methods

Fee operations require your API secret and must run on the server.

Method	Purpose
`getFeeBalances(apiSecret)`	Retrieves claimable fee balances for your organization.
`claimFees(params, apiSecret)`	Claims accrued fees to a recipient currency and address.

const { data, error } = await apiClient.getFeeBalances(
  process.env.COIN_VOYAGE_API_SECRET!
);