Snowflake CREATE PROCEDURE support

Support for https://docs.snowflake.com/en/sql-reference/sql/create-procedure, for example:
```sql
CREATE OR REPLACE PROCEDURE get_top_sales()
RETURNS TABLE ()
```

Currently parsing fails:

> Expected: [EXTERNAL] TABLE or [MATERIALIZED] VIEW or FUNCTION after CREATE OR REPLACE, found: PROCEDURE

Start with the parser path that handles CREATE OR REPLACE and compare its current accepted forms with the Snowflake CREATE PROCEDURE example in the issue. Add coverage for the shown statement and verify that parsing no longer reports PROCEDURE as unexpected.

Written by the indexing model from the issue text.