[TD-5356]<enhance>: default numOfMnodes to 1 instead of 3

[TD-5558]<fix>: fix invalid read memory issue

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

* slove conflict

* [TD-5506]<fix>: throw SQLException in HttpClientPoolUtil

[TD-5512]<fix>: fix arbitrator offline caused by vnode destroying

* [TD-4068]<feature>: taosdemo support stmt.

for easy merge purpose. disabled in master.

* fix clang compile error.

* fix memory leak, add more macros. change sqlcount to int

* fix rest segfault.

* add stmt_errstr() for reason print.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

* [TD-3197]<fix>: taosdemo and taosdump coverity scan issues.

* exit if read sample file failed.

* fix converity scan issue.

* fix coverity scan issue.

* fix coverity scan memory leak.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

* [TD-5479]<fix>: taosdump -S -E does not work.

* taosdemo support timestamp step from command line.

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

* merge jdbc update on develop into master

* remove useless test cases

* change

* change

* remove uneccesary test case

* change

[TD-5431]<fix>:taken into accout data length when compare nchar bytes

[TD-5338]<test>:test stable interval function

* [TD-5479]<fix>: taosdump -S -E does not work.

* taosdemo support timestamp step from command line.

release/ver-2.0.20.10

sync from develop branch.

* copy from develop branch. stmt: 0, nanosec: 0

* set thread name disabled on master branch.

Dkj master pull request to fix metrict_del.sim

* [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.

* remove space between columns and tags.

* change sql buffer to 1M align with taosdef.h.

* column buffer length be calculated.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>

modify all release scripts to adding "beta" in package name

* [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>

[TD-5338]support dummy tag in sub-table interval query

[TD-5388]<fix>: fix isUpdateQuery for 'reset query cache' statement

* [TD-5300]<fix>: taosdemo stmt debug print.

* fix default iface is unknown.

* merge with TD-5300 fix against develop

Test/td 5206 m