feat: add heartbeat and performance_schema tables

fix(os): const ptr is passed to free()

feat(query): support now()/today() function in select clause

feat: add affected rows

* [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

enh(cluster): enable tsim to support valgrind startup

TD-14243

enh(cluster): adjust show message handle

feat: performance_schema related SHOW statements are rewritten, and KILL statements build the message

refactor(tmq): persist ast in topic

feat: performance_schema related SHOW statements are rewritten, and KILL statements build the message

refactor: vnode

enh(query): improve the validity check of function parameters

fix concat crash bug

fix(test): enterprise test.