* [TD-182]<enhance>: use single repo for python connector

Remove code for each platform and build up one single python code base
for windows/osx/linux platforms and python2/python3 runtime.

* [TD-182]<enhance>: remove redundant code in python connector

* [TD-4149] <fix>: fix python connection config error

* [TD-4048] <fix>: fix python connector error where ts is null

* [TD-4048] <fix>: bump py connector version to 2.0.9

Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

[TD-769]