Merged PR 4568: Adds flag to identify invoices/credit notes that are posted in Hyperline

# Description

Adds flag to identify invoices/credit notes that are posted in Hyperline.
For Invoices, these need to be ACCREC and follow a convention of 20XX-Y
For Credit Notes, these need to be ACCRECCREDIT and follow a convention of CN-20XX-Y

# Checklist

- [X] The edited models and dependants run properly with production data.
- [X] The edited models are sufficiently documented.
- [X] The edited models contain PK tests, and I've ran and passed them.
- [X] I have checked for DRY opportunities with other models and docs.
- [X] I've picked the right materialization for the affected models.

# Other

- [ ] Check if a full-refresh is required after this PR is merged.

Related work items: #28146

models/intermediate/xero/int_xero__credit_notes.sql

@@ -37,5 +37,10 @@ select
     was_fully_paid_on_date_utc,
     line_amount_tax_inclusiveness,
     updated_date_utc,
+    case
+        when credit_note_number ~ '^CN-20\d{2}-.*' and credit_note_type = 'ACCRECCREDIT'
+        then true
+        else false
+    end as is_credit_note_posted_in_hyperline,
     dwh_extracted_at_utc
 from stg_xero__credit_notes