[TD-13970]<feature>: timestamp format shortcut

[TD-13875]<fix>: common json now can be inserted

add test cases for hyperloglog

* [TD-13836]<fix>: fix jdbc parse fetchblock data errors

* [TD-13836]<fix>: format convert

* [TD-13836]<fix> : fix NPE exception

* [TD-13836]<fix>: Uniform getTimeStamp API

* [TD-13836]<fix>: number value  return 0 when it's none

* [TD-13836]<fix>: fix related test cases

add docs for new function mode/tail/unique/stateCount/stateDuration/h…

[TD-13946]: fix bug caused by int16_t colBytes as head/tail/unique

[TS-1278]<fix>: fix isNull parameter with cols merge

[TD-11216]<feature>: Time window related keywords add  _qstart/_qstop/_qduration

* remove out-dated links

* refine taostools section

* adjst descriptions

* fix typo

* fix taosBenchmark doc link

* update documentation20/cn/02.getting-started/docs.md

* [TD-13571]<docs>: fix outdated

16KB => 64KB

* udpate schemaless section

* fix typo

* refine doc

[TD-5902]<enhance>: Support rcf3339 format timestamp in tag

Feature/td 13893 hyperloglog function

_qstart/_qstop/_qduration