* [regression](fix) 1. fix broker load test case and add orc test 2. set enableBrokerLoad=true in pipeline
* add a load test for the orc file and let it run in the TeamCity pipeline.
--This pr may not pass P0 Regression check since the bug of orc load has not been fixed.--
change the column name in the load sql to lowercase to pass P0 Regression check.
corrected: it's not a bug but a feature.