Fix metrics ingestion and add test

Author: b-per

integration_tests/models/marts/metrics.yml

@@ -34,4 +34,6 @@ metrics:
     type: simple 
     type_params:
   # Specify the measure you are creating a proxy for. 
-      measure: total_count 
+      measure: total_count 
+    filter: |
+      {{ Dimension('dim__id') }} > 0

macros/unpack/get_metric_values.sql

@@ -20,11 +20,11 @@
             wrap_string_with_quotes(node.type),
             wrap_string_with_quotes(dbt.escape_single_quotes(node.label)),
             wrap_string_with_quotes(node.package_name),
-            wrap_string_with_quotes(node.filter),
+            wrap_string_with_quotes(node.filter | tojson),
             wrap_string_with_quotes(node.type_params.measure.name),
             wrap_string_with_quotes(node.type_params.measure.alias),
-            wrap_string_with_quotes(node.type_params.numerator),
-            wrap_string_with_quotes(node.type_params.denominator),
+            wrap_string_with_quotes(node.type_params.numerator | tojson),
+            wrap_string_with_quotes(node.type_params.denominator | tojson),
             wrap_string_with_quotes(node.type_params.expr),
             wrap_string_with_quotes(node.type_params.window),
             wrap_string_with_quotes(node.type_params.grain_to_date),