[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' );