Merged PR 3419: Adds Host Resolutions metrics in new KPIs

# Description

Adds 2 new metrics:
- xero_host_resolution_amount_paid_in_gbp
- xero_host_resolution_payment_count

Effectively it will split the "real" invoicing sources of revenue from "host resolution payments". This was already reading from 2 different Xero models (bank transactions vs. sales).

We have as usual:
- 1 Daily metric model
- 2 MTD/Monthly metric model
- 2 MTD/Monthly agg model (I already changed the name to agg instead of aggregated)
- 1 test to compare the values match the current setup

# 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: #23565

models/intermediate/kpis/int_kpis__agg_mtd_host_resolutions.sql

@@ -0,0 +1,27 @@
+{% set dimensions = get_kpi_dimensions_per_model("HOST_RESOLUTIONS") %}
+
+{{
+    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(
+            xero_host_resolution_amount_paid_in_gbp
+        ) as xero_host_resolution_amount_paid_in_gbp,
+        sum(xero_host_resolution_payment_count) as xero_host_resolution_payment_count
+    from {{ ref("int_kpis__metric_mtd_host_resolutions") }}
+    group by 1, 2, 3, 4
+    {% if not loop.last %}
+        union all
+    {% endif %}
+{% endfor %}