Merged PR 4236: Propagate contact name for reporting purposes only

# Description

Propagates contact name and id_deal + contact name combination for PBI in xero - sales monthly trends

# 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.

Propagate contact name for reporting purposes only

Related work items: #26618

models/reporting/xero/schema.yml

@@ -1455,6 +1455,14 @@ models:
         data_tests:
           - not_null
 
+      - name: contact_name
+        data_type: text
+        description: "The name of the contact associated with the deal."
+
+      - name: id_deal_contact_name
+        data_type: text
+        description: "A concatenation of the deal ID and contact name."
+
       - name: accounting_financial_l1_aggregation
         data_type: text
         description: "The Level 1 aggregation for Financial reporting."