* [TD-5398]<fix>: taosdemo 4096 columns table creation failed.

* change column name prefix from col to c for maxium column number to fix buffer length.

* use accurate buffer length.

* fix test case for column name be shorter.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

* cherry pick from develop branch.

* [TD-5136]<feature>: taosdemo simulate real senario.

* update test case according to taosdemo change

* adjust range of semi-random data.

btw, solve two taosdemo test cases too.

[TD-4422]-adding test cases for different combination of drop, child_table_exist, and auto_create_table

* [TD-4136]<fix>: taosdemo max records per req < 32767

* [TD-4136]<fix>: taosdemo check insert rows not more than 32767.

check insert rows for progressive.

* fix with answer_yes.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

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

[TD-4037]<test>: add taodemo-testcase that childtable_count is less than or equal zero and num_of_records_per_req  is  equal zero

* [TD-3906]<fix>: taosdemo back to 4 INT columns.

* [TD-3906]<fix>: taosdemo back to 4 columns.

test case need change correspondingly.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>