Add checkDepositFreeze that checks the depositor for regular freeze and
the destination pseudo-account for deep freeze only. A regular freeze on
the vault account's trust line no longer blocks deposits.
Update checkWithdrawFreezes to skip the submitter freeze check when
submitter == destination (withdrawing to self).
Gate VaultDeposit with fixCleanup3_3_0; pre-fix path preserves the old
isFrozen-based checks. Use checkDepositFreeze in LoanBrokerCoverDeposit.