sqlc: add support for 'sql_driver' go gen option

sqlc lacks documentation on sql_driver setting
however setting is referenced in multiple places in their documentation
the inputs and validation was done based on the latest sqlc code v1.27.0

sqlc/kcl.mod

@@ -1,5 +1,5 @@
 [package]
 name = "sqlc"
 edition = "v0.9.0"
-version = "0.0.3"
+version = "0.0.4"
 description = "sqlc.dev schema config file"

sqlc/sqlc.k

@@ -167,6 +167,10 @@ schema GoGen:
     # Either `pgx/v4`, `pgx/v5` or `database/sql`.
     # Defaults to database/sql.
     sql_package: "database/sql" | "pgx/v4" | "pgx/v5" = "database/sql"
+    # One of the following drivers are allowed, the default value will depend on the sql_package
+    # and is handled by sqlc behavior:
+    # "github.com/jackc/pgx/v4" | "github.com/jackc/pgx/v5" | "github.com/lib/pq" | "github.com/go-sql-driver/mysql"
+    sql_driver?: "github.com/jackc/pgx/v4" | "github.com/jackc/pgx/v5" | "github.com/lib/pq" | "github.com/go-sql-driver/mysql"
     # If true, add DB tags to generated structs. Defaults to false.
     emit_db_tags: bool = False
     # If true, include support for prepared queries. Defaults to false.

sqlc/sqlc_test.k

@@ -293,6 +293,7 @@ sql:
         out: "some/path"
         omit_unused_structs: true
         emit_sql_as_comment: true
+        sql_driver: "github.com/go-sql-driver/mysql"
   - name: "test_two"
     schema: "schema.sql"
     queries: "query.sql"