serssion, server: fix the correctness of the query field in the DDL job

[zimulala]

What problem does this PR solve?

Problem Summary:

	_, err = tk.Se.Execute(context.Background(), "show create table t")
	id, _, _, err := tk.Se.PrepareStmt("CREATE TABLE t2(id bigint PRIMARY KEY, age int)")
	...

	// Before this PR, this DDL job's Query is "show create table t".
	// After this PR,  this DDL job's Query is "CREATE TABLE t2(id bigint PRIMARY KEY, age int)".
	_, err = tk.Se.ExecutePreparedStmt(context.Background(), id, params)

If the DDL job's Query field is wrong, the binlog content will be wrong. We don't set the value of sessionctx.QueryString in ExecutePreparedStmt.

What is changed and how it works?

What's Changed: ExecutePreparedStmt will also be set to the value of sessionctx.QueryString.

Check List

Tests

• Unit test

Release note

Fix the correctness of the query field in the DDL job

[zimulala]

PTAL @wjhuang2016 @AilinKid @coocood

[AilinKid]

Rest LGTM

[wjhuang2016]

LGTM

[AilinKid]

LGTM

[codecov]

Codecov Report

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The diff coverage is n/a.

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[sre-bot]

Your auto merge job has been accepted, waiting for 15415

[sre-bot]

/run-all-tests

[sre-bot]

cherry pick to release-3.0 in PR #15443

[sre-bot]

cherry pick to release-3.1 in PR #15444