* [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: Shuduo 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.
* [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: Shuduo Sang <sdsang@taosdata.com>