* AugmentedCDP type, codec registration, querier update
* added unique error for augmented cdp loading
* added AugmentedCDPs type for cdps query res
* query results for cdps (by denom) & cdps-by-ratio (by denom & ratio)
* status: converting collateral value into debt coin denom
* collateral value denominated in debt coin
* query cdps-by-ratio now searches by collateralization ratio instead of absolute ratio
* updated alias, code comments
* updated querier tests
* support multiple principal coins and their associated fees
* collateralization ratio calculations on updated fees
* include calculated fees in total debt calculation