Withdraw authority no longer implies a custodian (#11302)

* Withdraw authority no longer implies a custodian

Before this change, if the withdraw authority and custodian had
the same public key, then a withdraw authority signature would
imply a custodian signature and lockup would be not be enforced.

After this change, the client's withdraw instruction must
explictly reference a custodian account in its optional sixth
account argument.

Likewise, the fee-payer no longer implies either a withdraw
authority or custodian.

* Fix test

The test was configuring the stake account with the fee-payer as
the withdraw authority, but then passing in a different key to
the withdraw instruction's withdraw authority parameter. It only
worked because the second transaction was signed by the fee-payer.

core/src/non_circulating_supply.rs

@@ -23,14 +23,14 @@ pub fn calculate_non_circulating_supply(bank: &Arc<Bank>) -> NonCirculatingSuppl
         let stake_account = StakeState::from(&account).unwrap_or_default();
         match stake_account {
             StakeState::Initialized(meta) => {
-                if meta.lockup.is_in_force(&clock, &HashSet::default())
+                if meta.lockup.is_in_force(&clock, None)
                     || withdraw_authority_list.contains(&meta.authorized.withdrawer)
                 {
                     non_circulating_accounts_set.insert(*pubkey);
                 }
             }
             StakeState::Stake(meta, _stake) => {
-                if meta.lockup.is_in_force(&clock, &HashSet::default())
+                if meta.lockup.is_in_force(&clock, None)
                     || withdraw_authority_list.contains(&meta.authorized.withdrawer)
                 {
                     non_circulating_accounts_set.insert(*pubkey);