Add back some previously removed utility functions to transfer

[gjermundgaraba]

To lessen the upgrade burden from v8 -> v10, we should add back some of the utility functions that many have relied upon in the past as deprecated (and remove them in another upcoming release) from transfer.

Some will have a slightly modified function signature, but keep the name and return something similar enough that it can be used without too much change.

The initial list of functions to add back:

• func (k Keeper) DenomPathFromHash(ctx sdk.Context, ibcDenom string) (string, error)
• func SenderChainIsSource(sourcePort, sourceChannel, denom string) bool
• func ReceiverChainIsSource(sourcePort, sourceChannel, denom string) bool
• func GetDenomPrefix(portID, channelID string) string
• func GetPrefixedDenom(portID, channelID, baseDenom string) string
• func GetTransferCoin(portID, channelID, baseDenom string, amount sdkmath.Int) sdk.Coin
• func ParseDenomTrace(rawDenom string) DenomTrace (will have to return Denom)