fix: withdrawal_tx_in_reference missing asign withdrawal_item

[Newt6611]

Summary

In builder withdrawal api case PlutusScriptWithdrawal missing assign back to withdrawal_item

Scope of Change

• whisky
• whisky-provider
• whisky-wallet
• whisky-csl
• whisky-common
• whisky-js

Type of Change

Please mark the relevant option(s) for your pull request:

Feature Change

Type of feature change:

1. New feature - non-breaking change which adds functionality

Maintenance

• Bug fix (non-breaking change which fixes an issue)
• Code refactoring (improving code quality without changing its behavior)
• Documentation update (adding or updating documentation related to the project)

Checklist

• My code is appropriately commented and includes relevant documentation, if necessary
• I have added tests to cover my changes, if necessary
• I have updated the documentation, if necessary
• All new and existing tests pass
• Both rust and wasm build pass