* restore .gitmodules

* Revert "[TD-13408]<test>: move tests out"

This reverts commit 3b050c8b64175c0d26b6bcafcba6c5a68ebf1477.

* revert 3b050c8b64175c0d26b6bcafcba6c5a68ebf1477

* immigrate file change from stand-alone repo to TDengine

for 2.4

* remove tests repository checkout
Co-authored-by: Ntangfangzhi <fztang@taosdata.com>

Subscription implemented
Continuous Query implemented
Fixed bugs when dealing with null values retrieved from tables
Removed unused code
Added basic performance test code

Docs
- Docs updated
  - include third party connectors links
  - local docs updated to web versions and fixed for compatability
Node
- Async added
- Deleted uncessary code
- Docs updated

Implemented higher level API to make it more modular
Using promises and callbacks
Argument binding is now available e.g query(select ? from ?).bind("*", "table")