Asserts that the account is a valid fee account: either one of the program singletons or the fee vault.
Transfers all lamports from a PDA (except for rent) to a destination account.
Transfers lamports from one account to another, handling the cases where the account
is either a PDA or a system account.
Transfers lamports, skipping the transfer if the to
account would not be rent exempt.
Transfers specified lamports from a PDA to a destination account.
Throws an error if less than rent remains in the PDA.