Merged PR 3391: Adds Check-Out, Cancelled and Billable Bookings

# Description

Adds Check-Out, Cancelled and Billable Bookings in the new KPI flow.

For each of these metrics, it includes:
* Daily model
* Monthly/MTD without dimension aggregates
* Monthly/MTD with dimension aggregates
* Schema entries for the abovementioned 5 models
* Temporary test to compare the different metrics against current production KPIs

I also implemented a quick performance fix that removes the dependency of Billable Bookings from Booking Charge Events, since Bookings table already contains the needed information.

# 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.
- [NA] 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: #23454

models/intermediate/kpis/int_kpis__aggregated_monthly_cancelled_bookings.sql

@@ -0,0 +1,24 @@
+{% set dimensions = get_kpi_dimensions_per_model("CANCELLED_BOOKINGS") %}
+
+{{
+    config(
+        materialized="table", unique_key=["end_date", "dimension", "dimension_value"]
+    )
+}}
+
+
+{% for dimension in dimensions %}
+    select
+        -- Unique Key --
+        start_date,
+        end_date,
+        {{ dimension.dimension }} as dimension,
+        {{ dimension.dimension_value }} as dimension_value,
+        -- Metrics --
+        sum(cancelled_bookings) as cancelled_bookings
+    from {{ ref("int_kpis__metric_monthly_cancelled_bookings") }}
+    group by 1, 2, 3, 4
+    {% if not loop.last %}
+        union all
+    {% endif %}
+{% endfor %}