Merged PR 2179: Computes aggregated metrics by deal id and exposes it to reporting

This PR creates 2 new models:
- `int_core__monthly_aggregated_metrics_history_by_deal`, which just gathers the information of the previously created models that compute the kpis by deal id.
- `core__monthly_aggregated_metrics_history_by_deal`, effectively a copy from intermediate to reporting

It also includes documentation of these 2 models, differences between these and the `mtd_aggregated_metrics` equivalents and references it to exposures. I took the opportunity to update the documentation of the `core__mtd_aggregated_metrics` now that it's a bit more mature.

This should be the last PR for the first draft of 'by deal' metrics.

Related work items: #17689

models/reporting/exposures.yaml

@@ -99,17 +99,20 @@ exposures:
   - name: main_kpis
     label: Main Business KPIs
     type: dashboard
-    maturity: medium
+    maturity: high
     url: https://app.powerbi.com/links/ynCnuqVPTr?ctid=862842df-2998-4826-bea9-b726bc01d3a7&pbi_source=linkShare&bookmarkGuid=81e69a3e-90dc-46d7-b313-ba55ca611945
     description: |
       A PBI report showcasing the main business KPIs of our company.
       
       Includes multiple high-level metrics updated in a daily basis,
       ensuring both a Month-to-date comprehension of our business and
-      a view on historic values on a month-by-month approach
+      a view on historic values on a month-by-month approach.
+
+      Additionally, it allows to retrieve similar KPIs at Deal level.
 
     depends_on:
       - ref('core__mtd_aggregated_metrics')
+      - ref('core__monthly_aggregated_metrics_history_by_deal')
 
     owner:
       name: Oriol Roqué