updates the create schema statement

Adds authorization based on the create schema syntax defined by Microsoft. 
https://docs.microsoft.com/en-us/sql/t-sql/statements/create-schema-transact-sql?view=sql-server-ver15#remarks

Author: vigyuv

dbt/include/sqlserver/macros/adapters/schema.sql

@@ -1,9 +1,10 @@
 {% macro sqlserver__create_schema(relation) -%}
+{% auth = config.get("auth") %}
   {% call statement('create_schema') -%}
     USE [{{ relation.database }}];
     IF NOT EXISTS (SELECT * FROM sys.schemas WHERE name = '{{ relation.without_identifier().schema }}')
     BEGIN
-    EXEC('CREATE SCHEMA [{{ relation.without_identifier().schema }}]')
+    EXEC('CREATE SCHEMA [{{ relation.without_identifier().schema }}] {%- if auth -%} AUTHORIZATION: [{{auth}}]')
     END
   {% endcall %}
 {% endmacro %}