Replace hash with cosmos address

[NicolasMahe]

We should encode the resources' hashes in cosmos address.
The advantage are:

• bech32. it has prefix and checksum
• can be use in bank module and thus transfer coins
• easier for the user to have a common hash/address system across the whole system.

I did some POC and I come with those conclusions:

• converting the current hash to address, specifically to AccAddress is super easy: Use type accAddress instead of hash.Hash for resources' hash #1704
• But it means all type of resource will use the same prefix. cosmos-sdk is planning to support address type (Extensible address format cosmos/cosmos-sdk#5694). this will solve this issue. Check the POC: Specific address for every type of resource #1716