Clone a receivable

Creates a copy of an existing accounts receivable invoice or quote. The original document can be in any status. The cloned document will have the `draft` status. Cloning a document requires that all of the referenced resource IDs (counterpart ID, product IDs, and others) still exist. Most of the original document's data is copied as is, with a few exceptions: * Some fields are not copied: `attachments`, `document_id`, `issue_date`, invoice `payment_page_url`, quote `expiry_date`. * Counterpart details, entity bank account details, and entity VAT number are fetched anew from their corresponding IDs. This means, for example, that if the counterpart details have been changed since the original invoice or quote was created, the cloned document will use the current counterpart details rather than the old details from the original document.