new a/b test model in reporting and updated exposure

models/intermediate/core/schema.yml

@@ -4174,12 +4174,6 @@ models:
       a bit of open possibilities for whenever we're analysing results later on. This is 
       already materialised to avoid running long queries in the notebooks.
 
-    data_tests:
-      - dbt_utils.unique_combination_of_columns:
-          combination_of_columns:
-            - id_verification_request
-            - ab_test_name
-
     columns:
       - name: id_verification_request
         data_type: integer
@@ -4189,24 +4183,18 @@ models:
           can be part of none, one, or several A/B tests. 
           In this table, a Verification Request or Guest Journey can only appear once per A/B test.
           Cannot be null.
-        data_tests:
-          - not_null
 
       - name: ab_test_name
         data_type: string
         description: |
           Name of the Guest Journey A/B test. It corresponds to the Feature Flag Name in the 
           backend. Cannot be null.
-        data_tests:
-          - not_null
 
       - name: variation
         data_type: string
         description: |
           Identifier of the variation a given Verification Request is in, within a
           given Guest Journey A/B test. Cannot be null.
-        data_tests:
-          - not_null
 
       - name: first_appearance_at_utc
         data_type: timestamp
@@ -4214,8 +4202,6 @@ models:
           Timestamp of the first Verification Request Feature Flag record created 
           with the same verification request and A/B test name. Mostly for information 
           purposes. Cannot be null.
-        data_tests:
-          - not_null
 
       - name: first_appearance_date_utc
         data_type: date
@@ -4223,8 +4209,6 @@ models:
           Date of the first Verification Request Feature Flag record created 
           with the same verification request and A/B test name. Mostly for information 
           purposes. Cannot be null.
-        data_tests:
-          - not_null
 
       - name: verification_started_date_utc
         data_type: date