Merged PR 4958: Add compare tables macro

# Description

Adds a macro to compare the contents of two tables. Will simply tell you if the contents are identical or not. Designed to be used in your development flow through the CLI so you can check refactors as you go.

macros/compare_table_hashes.sql

@@ -0,0 +1,50 @@
+/* 
+Query all columns in two models, reduce the table to a content hash and compare
+the hashes across both.
+
+You must pass a col name that exists in both models to sort them in order to 
+make serialization stable. It is recommended to pass the PK.
+*/
+{% macro compare_table_hashes(model_1, model_2, order_by_col) %}
+
+    {% set table_1 = ref(model_1) %}
+    {% set table_2 = ref(model_2) %}
+
+    {# Build query 1 #}
+    {% set query_1 %}
+    SELECT md5(array_agg(md5((t1.*)::varchar))::varchar) AS hash_val
+    FROM (
+      SELECT *
+      FROM {{ table_1 }}
+      ORDER BY {{ order_by_col }}
+    ) AS t1
+    {% endset %}
+
+    {# Build query 2 #}
+    {% set query_2 %}
+    SELECT md5(array_agg(md5((t1.*)::varchar))::varchar) AS hash_val
+    FROM (
+      SELECT *
+      FROM {{ table_2 }}
+      ORDER BY {{ order_by_col }}
+    ) AS t1
+    {% endset %}
+
+    {# Execute queries #}
+    {% set result_1 = run_query(query_1) %}
+    {% set result_2 = run_query(query_2) %}
+
+    {% if result_1 and result_2 %}
+        {% set hash_1 = result_1.columns[0].values()[0] %}
+        {% set hash_2 = result_2.columns[0].values()[0] %}
+
+        {{ log("Hash for " ~ model_1 ~ ": " ~ hash_1, info=True) }}
+        {{ log("Hash for " ~ model_2 ~ ": " ~ hash_2, info=True) }}
+
+        {% if hash_1 == hash_2 %} {{ log("✅ Table hashes match!", info=True) }}
+        {% else %} {{ log("❌ Table hashes do NOT match!", info=True) }}
+        {% endif %}
+    {% else %}
+        {{ log("❗ Could not retrieve hashes for one or both models.", info=True) }}
+    {% endif %}
+{% endmacro %}