ExchangeRateResponse is data format returned from OracleRequest::ExchangeRate query
HumanPrice is returned from the oracle querier and is a decimal value
representing the exchange rate of the given denom, without any normalization.
This is a helper wrapper to easily use our custom queries
NormalizedPrice should be used in all operations involving
calculating the value of coins given the oracle price.
When comparing values of non-standard denominations, failing
to normalize the price can cause unexpected and incorrect results.