### Description of the issue/feature this PR addresses:
Fixes an issue where timesheets lose their invoice reference when reversing and re-creating an invoice via a credit note.

### Current behavior before PR:
When reversing an invoice tied to timesheets and creating a replacement via a credit note, the timesheets linked to the original invoice have their timesheet_invoice_id cleared. Because the modify_moves function builds the replacement invoice directly via copy_data()/create(), it bypasses the normal sale order invoicing flow. As a result, the unbilled timesheets are left permanently unlinked from the newly created invoice, leaving the new invoice with no reference to the timesheets linked to the original sale order.

### Desired behavior after PR is merged:
When a replacement invoice is created, each timesheet is properly relinked to the corresponding line on the new invoice. This linkage matches on the sale order line (so_line) rather than line position, ensuring accuracy since line order and count are not guaranteed to be preserved between the original and modified invoices.

opw-6449995

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