Merged PR 3810: Adds is_end_of_month_or_yesterday for Main KPIs

# Description

Adds `is_end_of_month_or_yesterday` for Main KPIs.
Apparently, the fact that we do not show the ongoing value of the month on some tabs of Main KPIs is the main blocker for Ben C to consistently use Main KPIs, which he actually retrieves from the SH legacy reporting. Since I'm sceptical about the data shown there, I want to remove this blocker.
It will require a small PR on PBI as well.

# 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.
- [NA] 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: #25342

models/intermediate/cross/schema.yml

@@ -212,7 +212,13 @@ models:
 
       - name: is_end_of_month
         data_type: boolean
-        description: is end of month, 1 for yes, 0 for no.
+        description: True if it's end of month.
+        tests:
+          - not_null
+
+      - name: is_end_of_month_or_yesterday
+        data_type: boolean
+        description: True if it's end of month or yesterday.
         tests:
           - not_null