parser, ddl: correct the job type of 'REORGANIZE PARTITION'

[bb7133]

What problem does this PR solve?

Issue Number: close #42442

Problem Summary:

What is changed and how it works?

See the comments in #42442:

The root cause is that we didn't mark "reorganize partition" as "need backfill" so it is scheduled as the 'general job', and the 'general job' is scheduled in serial(always block each others).

This PR simply fixes this.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)

Like #42442, concurrently run CREATE TABLE and REORGANIZE PARTITION in 2 sessions:

session1(first)> alter table t1 reorganize partition p0, p1, p2, p3, p4 into( partition pnew values less than (10000000));
session2(second)> create table t01(a int, b int);

We can verify that create table will not be blocked anymore.

• No code

Side effects

• None

Documentation

• None

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• hawkingrei
• xhebox

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[bb7133]

"Release note" is NONE because bug #42442 is not released yet.

[xhebox]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: a403bba

[YangKeao]

LGTM

[hawkingrei]

/retest

[hawkingrei]

/retest

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.0: #42494.