time: fix the fraction loss when encountering time string with timezone suffix

[Qiaolin-Yu]

What problem does this PR solve?

Issue Number: close #35291

Problem Summary:

What is changed and how it works?

Identify the position of the timezone before identifying the position of the fraction in the time string to avoid the accuracy loss. Timezone will also be checked later to ensure compatibility so that there is duplicate detection for timezone.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

DROP TABLE IF EXISTS `testSetObjectTime`;
CREATE TABLE `testSetObjectTime` (
  `id` int(11) DEFAULT NULL,
  `d` time(6) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;
INSERT INTO testSetObjectTime VALUES (1, '2020-01-01 12:00:00.123456000+05:00');
INSERT INTO testSetObjectTime VALUES (2, '2020-01-01 12:00:00.123456+05:00');
SELECT * FROM testSetObjectTime;

+------+-----------------+
| id   | d               |
+------+-----------------+
|    1 | 15:00:00.123456 |
|    2 | 15:00:00.123456 |
+------+-----------------+

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

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:

• LittleFall
• XuHuaiyu

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[Qiaolin-Yu]

/cc @AilinKid

[Qiaolin-Yu]

/cc @bestwoody

[Qiaolin-Yu]

/cc @XuHuaiyu

[bestwoody]

lgtm

[ti-chi-bot]

@bestwoody: Thanks for your review. The bot only counts approvals from reviewers and higher roles in list, but you're still welcome to leave your comments.

In response to this:

lgtm

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[ti-srebot]

cherry pick to release-5.0 in PR #37990

[ti-srebot]

cherry pick to release-5.1 in PR #37991

[ti-srebot]

cherry pick to release-5.2 in PR #37993

[ti-srebot]

cherry pick to release-5.3 in PR #37994

[ti-srebot]

cherry pick to release-5.4 in PR #37999

[ti-srebot]

cherry pick to release-6.1 in PR #38009

[ti-srebot]

cherry pick to release-6.2 in PR #38010

[ti-srebot]

cherry pick to release-6.3 in PR #38017

[sre-bot]

TiDB MergeCI notify

🔴 Bad News! [3] CI still failing after this pr merged.
These failed integration tests don't seem to be introduced by the current PR.

CI Name	Result	Duration	Compare with Parent commit
idc-jenkins-ci-tidb/common-test	🔴 failed 1, success 10, total 11	52 min	Existing failure
idc-jenkins-ci-tidb/integration-ddl-test	🔴 failed 1, success 5, total 6	23 min	Existing failure
idc-jenkins-ci-tidb/tics-test	🔴 failed 1, success 0, total 1	4 min 2 sec	Existing failure
idc-jenkins-ci/integration-cdc-test	🟢 all 37 tests passed	33 min	Existing passed
idc-jenkins-ci-tidb/integration-common-test	🟢 all 17 tests passed	9 min 33 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-2	🟢 all 28 tests passed	4 min 55 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-1	🟢 all 26 tests passed	4 min 35 sec	Existing passed
idc-jenkins-ci-tidb/mybatis-test	🟢 all 1 tests passed	3 min 5 sec	Existing passed
idc-jenkins-ci-tidb/integration-compatibility-test	🟢 all 1 tests passed	2 min 47 sec	Existing passed
idc-jenkins-ci-tidb/plugin-test	🟢 build success, plugin test success	4min	Existing passed