Encodes DelegationManager.completeQueuedWithdrawals(withdrawals, tokens, receiveAsTokens).
Completes completable withdrawals for the staker in a single batch transaction.
Token addresses are resolved automatically. Can only be called after the escrow period has passed for at least one withdrawal.
Set undelegatedOnly=true to only complete withdrawals from the undelegation queue (for redelegation).

Nonce handling: The nonce is computed at call time. If you prepare multiple transactions before broadcasting, they will share the same nonce and only the first will succeed. Broadcast and confirm each transaction before preparing the next.