Merged PR 4349: Xero metrics by Business Scope

# Description

Changes:
* Creation of a deal-based model that contains when a "deal has appeared in new dash". This is tricky because a Deal can still have multiple users, thus it needs to be attributed to a date. I've chosen the first user appearance for the rest of the metrics.
* Adaptation of dimension deals in KPIs to include a client type, that indicates if the deal is from APIs or not (Platform, i.e., Dashboard).
* Xero metrics by Business Scope. This is the previous "dash source" that I need to change in the previously worked models. I decided to include APIs in the segmentation since in most cases we distinguish old dash from new dash by just "anything that is not in new dash". This is very wrong for invoicing metrics, in which we have APIs. So this actually properly computes a client segmentation by scope.

Note that I'll need to handle the monthly/mtd metrics/agg for these 2 metric models (Resolutions + Invoiced revenue) separately.

# 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: #27356

dbt_project.yml

@@ -65,6 +65,9 @@ vars:
   # KPIs Start Date. This is the date from which we start calculating KPIs.
   "kpis_start_date": "'2022-04-01'"
 
+  # New Dash First Invoicing Date. This is the first date considered for New Dash invoicing.
+  "new_dash_first_invoicing_date": "'2024-12-31'"
+
   # A distant future date to use as a default when cutoff values are missing.
   "end_of_time": "'2050-12-31'"