* [TD-13558]<feature>: taos shell refactor
add taosTools as submodule
* add tools/taos-tools
* add more client interface for taosTools compile
* update taos-tools
* update taos-tools
* refactor shell
* [TD-13558]<feature>: taos shell test speed
* [TD-13558]<feature>: taos -n startup works
* taos -n rpc works
* taos -n server works
* cleanup code since no endPort in 3.0
* update taos-tools
* [TD-13558]<feature>: taos -C works
* improve taos shell -c WIP
* update taos-tools
* add demoapi.c
* adjust show databases result for 3.0
* test: add platform logic
* add nchar
* adjust taos_fetch_lengths
* print fields
* remove show databases check from insert cases
* fix lua example compile for 3.0
still not work
* remove lua.py from smoketest
* use get_column_data_offset() to get offset and convert length
* Add support for async query. Only insert result is parsed.
* Add support for connection pool.
* Add one case for lua connector in smoke test case list.
* Build dymanic library for lua connector before smoke test.
* [TD-4025]<fix>: travis ci broken due to valgrind dependency missed.
modify smoketest.sh to python3.8
* [TD-4025]<fix>: travis ci broken due to ubuntu 20.04 repo issue.
* [TD-4025]<fix>: travis ci broken due to ubuntu 20.04 repo issue.
* [TD-4025]<fix>: travis ci broken due to ubuntu 20.04 repo issue.
* [TD-4025]<fix>: travis ci broken due to valgrind dependency missed.
change focal to bionic.
* [TD-4025]<fix>: travis ci broken due to ubuntu 20.04 repo issue.
cherry pick from master.
Co-authored-by: Shuduo Sang <sdsang@taosdata.com>