Support withdrawal address in gentx/ create-validator

[alpe]

We could have the withdrawal-address in the gentx and create-validator msg already.
The process are 2 steps currently where the validator-operator has to set the withdrawal address after the chain is launched.

[ethanfrey]

I think vesting accounts handle this. If I have 100 vesting tokens and you send me 50, those 50 are immediately available to bank send

We need to verify in code and in tests.

[alpe]

When I tried to spent rewards while tokens from a vested account were staked, it was not possible.
Only when balance > locked amount, the test passed. This is the sdk code called in send:
https://github.com/cosmos/cosmos-sdk/blob/v0.45.0/x/bank/keeper/send.go#L183

With a withdrawal address the rewards would be accessible

[alpe]

I am moving this to a "post mainnet" milestone to be pulled in when there is enough capacity or be closed. This issue is optimizing a rare use case for the setup phase only