Don't validate validator addresses

[webmaster128]

In some places in MultiTest, validator addresses are validated with let val_addr = api.addr_validate(&validator.address)?;. But the validator addresses are not the same as regular account addresses. I.e. I cannot use MultiTest to test with validator addresses.

Usually they have a different prefix, like mychainvaloper1... instead of mychain1.... This is the reason why they are always typed as String in cosmwasm-std, not Addr. The Addr type only works for user addresses.

So we need to avoid the use of the Addr type in the staking implementation:

• const VALIDATOR_MAP: Map<&Addr, Validator> = Map::new("validator_map");
• const VALIDATOR_INFO: Map<&Addr, ValidatorInfo> = Map::new("validator_info");
• pub validator: Addr,
• fn add_validator
• StakingMsg::Delegate implementation
• StakingQuery::Delegation implementation
• ...