[hotfix] Supports specifying routing fields

[ethan-xiao]

Supports specifying routing fields during write operations. Parameter name: sink.partition-routing.fields

e.g.
create temporary table order_info_sink (
id BIGINT,
user_id BIGINT,
order_id BIGINT,
PRIMARY KEY (id) NOT ENFORCED
) WITH(
'connector' = 'elasticsearch-7',
'hosts' = 'http://127.0.0.1:9200/',
'index' = 'order_info',
'username' = 'elastic',
'password' = 'mypassword',
'sink.partition-routing.fields' = 'user_id'
);