refactor(query): set the block groupId for stream block.

docs: change city name

fix(query): fix unique function NULL value not hashable handling

enh: default ep set

enh: opt index mutex

fix: vnode pre-process

test：add test case for functions

test: modify case

TD-16034

docs: refine image alt text

test:add cluster testcase of electing leader and python connector using statement api

test: modify sleep value

feat(tmq): drop cgroup

Rewrote some sentences for readability.

Changed to: "In the above sample, `print_result` is used to simplify the printing of the result set. It is similar to `taos_use_result`"

feat: add tag version

Stylistic changes.
Clarifying changes.
Removed reference to taos_use_result since it is not mentioned in code snippet.

Minor changes for spelling and style.

Stylistic and grammar changes.

Grammar changes.

Spelling correction.