fix:change the default value of smlDataFormat

fix:change the default value of smlDataFormat

fix:add description of taos_get_current_db

fix:add description of schemaless interface

fix:add description of schemaless interface

fix:add description of taos_get_current_db

fix:modify description for schemaless

fix:modify description for schemaless

* docs: update csharp connector status

* docs: fix csharp ws bulk pulling

* docs: clarify database param is optional to websocket dsn

* docs: fix java connector mistake

* fix: a few typos

* fix: many typos

* docs: java connector support subscription over websocket

* enh: coverage

* enh: coverage, atomic

* fix: int to int8 error

* enh: delete unused code

docs: this line is inaccurate, in current connector-python repo, it require python >= 3.6.2 because there is a dependence iso8601 (#20336)
Co-authored-by: NAdam Ji <jrgwyz@163.com>

docs: add event window

docs: add event window

docs: add event window

release: update 3.0 version to 3.0.3.0

docs: release 3.0.3.0

update coverage test script