*: refine text protocol multiple query response

[lysu]

What problem does this PR solve?

fixes #11235

the current multi-query response has some problem

1. multi NoDelay executor(update/insert/delete) only return 1 ok packet, but mysql return N ok packets for N stmts

in tidb:

in mysql:

2. multi select return addition ok packet

s.addBatch("select 1");
s.addBatch("select 1");
System.out.println(Arrays.toString(s.executeBatch()));

tidb will return -1, -1, 0, but mysql need -1, -1.

this PR fix both problems, but leave #4617 to next (because it need change too many code)

What is changed and how it works?

• no-delay executor in multi-query also return a special recordSet - -
• writeMultiResultset take care special recordSet and write ok-packet for each record-set
• refine ServerMoreResultsExists set logic writeMultiResultset

Check List

Tests

• Integration test https://github.com/pingcap/tidb-test/pull/859

Code changes

• Has exported function/method change
• Has interface methods change

Side effects

• Increased code complexity

Related changes

• Need to cherry-pick to the release branch ?

[lysu]

/run-all-tests

[codecov]

Codecov Report

Merging #11263 into master will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff             @@
##             master     #11263   +/-   ##
===========================================
  Coverage   81.5609%   81.5609%           
===========================================
  Files           423        423           
  Lines         91301      91301           
===========================================
  Hits          74466      74466           
  Misses        11512      11512           
  Partials       5323       5323

[lysu]

/run-all-tests tidb-test=pr/859

[jackysp]

LGTM

[imtbkcat]

LGTM

[lysu]

/run-all-tests tidb-test=pr/859

[imtbkcat]

@lysu does it need to be cherry-picked to release-3.0?