add `create_table` combinator

[clarkevans]

This combinator would use the existing result as the body for
`create_table("table_name";
replace_if_exists=false,
schema=TRDW.user_schema(),
catalog=TRDW.env_catalog())

For now, we could grant ALL PRIVILEGES on schema and table to CTSIStaff.

I suppose this is an alternative to #83 since the output of this would be pure SQL. Therefore, I can see why this is preferable.

[clarkevans]

This combinator was added but it wasn't documented.