Merged PR 4898: Small adaptations to KPIs Outlier detector test

# Description

Changes:
* If metric is null don't compute test.
* Use 1 year data to compare against.
* For debugging purposes, compute also the amount of days used in the comparison.

The metric is not null is a necessary feature to avoid raising errors while there's no Host Resolutions in month. Keep in mind the test will keep failing and this is EXPECTED because of a massive increase in New Listings:
![image.png](https://guardhog.visualstudio.com/4148d95f-4b6d-4205-bcff-e9c8e0d2ca65/_apis/git/repositories/54ac356f-aad7-46d2-b62c-e8c5b3bb8ebf/pullRequests/4898/attachments/image.png)

# Checklist

- [X] The edited models and dependants run properly with production data.
- [ ] The edited models are sufficiently documented.
- [ ] The edited models contain PK tests, and I've ran and passed them.
- [ ] I have checked for DRY opportunities with other models and docs.
- [ ] I've picked the right materialization for the affected models.

# Other

- [ ] Check if a full-refresh is required after this PR is merged.

If metric is null don't compute test. 1y data to compare against.

tests/kpis_global_metrics_outlier_detection.sql

@@ -57,7 +57,7 @@ point it becomes too sensitive, just adapt the following parameters.
 -- means that this test will allow for more variance to be accepted,
 -- thus it will be more tolerant.
 -- A lower value means that the chances of detecting outliers 
--- and false positives will be higher. Recommended around 10.
+-- and false positives will be higher. Recommended around 5.
 {% set detector_tolerance = 5 %}
 
 -- Specify here the number of days in the past that will be used
@@ -66,7 +66,7 @@ point it becomes too sensitive, just adapt the following parameters.
 -- it means that we will take 1) all values of the current month
 -- except the latest update and 2) the end of month figures for the 
 -- past 6 months max.
-{% set timeline_to_compare_against = 180 %}
+{% set timeline_to_compare_against = 366 %}
 
 with
     max_date as (
@@ -90,6 +90,7 @@ with
             and dimension = 'Global'
             and date between max_date -{{ timeline_to_compare_against }} and max_date
             and metric in {{ metric_names }}
+            and value is not null
     ),
     metrics_to_validate as (
         select date, metric, value, abs_daily_value
@@ -107,7 +108,8 @@ with
                 0
             ) as lower_bound,
             avg(abs_daily_value)
-            + {{ detector_tolerance }} * stddev(abs_daily_value) as upper_bound
+            + {{ detector_tolerance }} * stddev(abs_daily_value) as upper_bound,
+            count(1) as days_used_for_computation
         from metric_data
         where is_max_date = 0
         group by 1
@@ -122,6 +124,7 @@ with
             mtca.std_daily_value_previous_dates,
             mtca.lower_bound,
             mtca.upper_bound,
+            mtca.days_used_for_computation,
             case
                 when
                     mtv.abs_daily_value >= mtca.lower_bound